[56RAT]

Sorry guys if this is a repost by someone, I tried searching and couldn't find anything. I am right in the middle of my suspension and I am hoping someone here can steer me in the right direction.

I want my car to sit as level as possible while keeping the lowered / tucked stance in tact. We just installed a 9" rear in my 56 with a 1" lowering block. We also installed a in the rail spring relocation kit at the same time and also installed caltrax.

I am running a 325/50/15 in the rear on a 10" wide w/ 5" bs and it fits very nice with my shortened rear. Up front I ordered a new power disc brake kit w/ 2" drop spindles.. My current front tires are way too small, I haven't even installed the drop spindles yet and I can tell once I do the front of my car will point way down and I don't want that. My current fronts are 205/60R15 ( 24.7") Before I order new front tires I need to know the following:



Question #1

With 2" drop spindles up front what is the tallest tire you can use without rubbing? I want the same tucked look on the front and back while having the car sit as level as possible. Can I fit a 235/75-15 or is that too tall? (28.9")

My front rims are a 15x7 with 4" back spacing. As I said my rear tires are 27.8" tall and I am running a 1" block. so with 2" drop spindles up front I will need to run a little bit taller tire than the rear to make it sit level or I will need to drop the rear even more. I just don't know if a 235/75/15 is even possible with drop spindles.

Question #2

If I need shorter tires up front for clearance issues what is the largest block you can run in the back without causing spring issues? Can I run a 2" block to at least try and help the car sit level? What is the trick for getting the tucked pro street look with drop spindles and still having it street friendly without rubbing everywhere you go?


Thanks guys.. I really appreciate it. I don't want to order a set of tires and waste my money if they wont work. I have never done a lowering kit on a tri5 before so it's all new to me. I have a image in my head of how I want it to look but making it happen in real life isn't as easy.

 

[Chevynut]

If you're only going to drop the front end 2" you shouldn't have too much trouble with it. Mine is dropped 3" in front and I don't anticipate and rubbing issues.

The overall width of the front tires seems to be more important than the diameter, to a point. The stock tires were a little over 28" in diameter. So try to keep the front tires at about 67.5" overall width outside to outside and you should be fine. With only a 2" drop, you may even be able to go wider than that.

Here's my Nomad with a C4 vette rear with a 2" suspension drop and 1" tire drop (295/35-18), and with a C4 vette front end with 3" suspension drop and 1" tire drop (245/45-17) in front.

 

[Rick_L]

1. The diameter of the front tire is a secondary factor in whether it rubs when steering. The tire width is the primary thing, along with wheel backspacing. Think of it this way: If you can move the whole tire out of the way by moving it away from the fender, that works regardless of tire height.

The usual rule of thumb with typical dropped spindles is that a 225 tire on a 7" rim with 4.5" backspacing will clear adequately. That's not to say it will 100% of the time under all conditions, but it will usually work.

2. How big a lowering block you can use is subjective. Lowering springs are usually preferred to a lowering block. If you drive your car hard, a lowering block puts more stress on the spring and u-bolt when you accelerate. And that gets real bad if you have wheel hop. Also, all lowering blocks are not created equal. You need to stay away from the hollow cast aluminum ones.

 

[56RAT]

So "most likely" I can get the 235/75-15 ( 28.9 ) tire to fit on a 7" rim with 4" bs and drop spindles? If you are saying a 225 usually fits with a 4.5" BS having that extra half inch to play with on the outside fender may come in handy for the 235 tire.

these are the tires I am looking at:

http://www.summitracing.com/parts/KUM-1909113/



I really want to keep the back where it is. I don't want to be forced into buying new springs and I really want to keep the block at a inch so I don't have any issues. Right now it doesn't look too bad IMO.. a 325/50/15 is a good size tire and it fits quite well.. I just need to focus on getting the front sitting where it needs to sit now. I really appreciate the help guys. The motor, blower, front suspension and transmission is ready to go in.. I just wanted to figure out my tire situation before I go any further.

 

[Chevynut]

So "most likely" I can get the 235/75-15 ( 28.9 ) tire to fit on a 7" rim with 4" bs and drop spindles? If you are saying a 225 usually fits with a 4.5" BS having that extra half inch to play with on the outside fender may come in handy for the 235 tire.

Where are you getting the "extra half inch"? Looks to me like you're losing a half inch to the fender, plus using a larger tire.

I really want to keep the back where it is.

The rear of your car seems awfully high for having 1" lowering blocks and stock springs. Is that at ride height? What is the clearance between your axle tube and the frame at the top of the hump?

Here's a stock 56:

 

[56RAT]

Where are you getting the "extra half inch"? Looks to me like you're losing a half inch to the fender, plus using a larger tire.




The rear of your car seems awfully high for having 1" lowering blocks and stock springs. Is that at ride height? What is the clearance between your axle tube and the frame at the top of the hump?

Here's a stock 56:

Sorry I must of been thinking backwards on the back spacing then. It always throws me off, I thought the rims would be 1/2" further in the car instead of further out-- my bad. Do they make a decent 215/225 tire that is around 27-28" tall?

We just barely put the car on the ground for the first time when that pic was taken today and the gas tank is still out and they are brand new shocks.. I figured once it settles it may sag another 1/2" or so. We used the stock springs with a 1" block. I am not sure why it didn't drop more? We have not drove it yet, I will need a new driveshaft first since we went with a 9" rear.

You are right though. I just looked at a pic of my car before we touched it and it is sitting almost the same in the pic as it is now. It had 25" tires on it before. Interesting.. The only thing I can think of is I put a little pre load on the caltrax without realizing it... I will go check after work. I don't see what else could cause this to happen. We used the same springs and installed a pocket kit with caltrax, new shocks and a 1" block.. The only thing that could affect the ride height is the caltrax.

 

[Rick_L]

Confusion has set in.

The 4.5" backspacing will move the tire IN as you thought, vs. 4.0" backspacing.

My recommendation was to use 7" rims, 4.5" backspacing, and 225 tires. I think you need them all to meet your stated goals, and even then you won't have it as narrow as Chevynut's recommendation. On the other hand, that's about all you can do with commonly available parts using the stock frame and suspension. So there is no room to "play with" anything. If you don't do all the above, you are compromised in some way. And a lot of cars you see are compromised in this area.

To do more you need an aftermarket suspension or a front frame clip. There are other issues too.

On the rear, I am with Chevynut, your rear stance is way above stock, and not just by 1/2" or even 1".

 

[56RAT]

Confusion has set in.


On the rear, I am with Chevynut, your rear stance is way above stock, and not just by 1/2" or even 1".

I don't understand what would cause this besides a caltrax preload issue. i am absolutely stumped and could use any guesses you guys may have. As you can see by the pic we created and welded the block right to the axle for extra support and better looks..

( don't laugh at the looks just yet we haven't painted it or cleaned it up yet. just fitting everything now )


This pic was taken before we added the caltrax bar. Will adding a pocket kit change the ride height at all with stock springs? I assume the ride height would stay the same? I will check the pre load in 10 minutes. If that checks out okay I have no idea what would cause it to sit the way it is. Feel free to throw out any guesses. Thanks for the replies guys, I am glad someone pointed it out because when I started this thread I was more concerned with tall front tires with drop spindles and my 15x7 4" bs rims.

 

[Chevynut]

Confusion has set in.

The 4.5" backspacing will move the tire IN as you thought, vs. 4.0" backspacing.

My recommendation was to use 7" rims, 4.5" backspacing, and 225 tires. /QUOTE]

Yes, I thought he was saying he would gain 1/2" with the 4" backspacing over the 4.5". I may have misunderstood the statment below. The deeper backspacing will move the wheel and tire inboard.

"So "most likely" I can get the 235/75-15 ( 28.9 ) tire to fit on a 7" rim with 4" bs and drop spindles? If you are saying a 225 usually fits with a 4.5" BS having that extra half inch to play with on the outside fender may come in handy for the 235 tire. "

Looking at your front end, it is pretty high too. 2" dropped spindles will put the fender right at the top of the tire, or so it appears. That won't give you much trouble with a wider front end, IMO. But if you start cutting springs, you will have trouble if you're much over 67.5" wide.

Let's assume you have the typical disc brake kit that moves your wheels out 3/8" per side. That makes your front end about 60" wide at the wheel mounting surfaces. If you use a 7" wheel with 4.5" backspacing, that's .5" positive offset. So the center of the tires would be at 59". Now add the width of a 235 tire and you're at 68.25". That's about 3/8" per side more than the recommended width. It might work ok with a 2" drop.

If you can, I'd try to get about 5" backspacing to bring the wheels in a little further. You won't get the "tucked in" look with that wide of a tire on a stock suspension.

 

[Rick_L]

Problem is, 4.5" backspace on a 7" wheel is not an "off the shelf" item for most wheels, it's either a special order or not available at all.

I don't think that even the billet wheel guys will build you a 5" backspace with a 7" wide rim. 4-1/2" or 4-3/4" is the limit with a 7" rim, depending on the manufacturer. I explored this with Budnik as I was discussing buying the wheels I bought from them.

The other problem with 4-1/2" backspacing, or more, is that you may be limiting your steering travel because the tire rubs the frame before you get full travel with the steering box and linkage. Taller tires make this worse than short tires, so this is an area where tire diameter does play a role.

The reduced steering angle may be liveable though, and tire rub to the fender may affect you the same way.

There is no pat answer to this question. Wheel mounting surface width, tire width, backspacing/wheel width, tire diameter, and ride height all play into this. Maybe other things.

 

[56Mark]

Just throwing out something I ran into once. Have you torqued the U-bolts on the back springs? If you just have them barely snug, it will come down a little more when you torque it. Doesn't seem like it would make much difference, but it flattens out the curve in the spring a little. When I first changed my rear springs mine was setting a little uneven side to side. Tightening all the U-bolts uniformly leveled it out.

 

[56RAT]

Problem is, 4.5" backspace on a 7" wheel is not an "off the shelf" item for most wheels, it's either a special order or not available at all.

I don't think that even the billet wheel guys will build you a 5" backspace with a 7" wide rim. 4-1/2" or 4-3/4" is the limit with a 7" rim, depending on the manufacturer. I explored this with Budnik as I was discussing buying the wheels I bought from them.
.

I am in luck.. I plan on running rallye rims on my car and they make a 7" with 4.5" BS rally rim and it's not very expensive. I am sure I can sell my current 4" backspacing rims without a problem if I need to switch rims.

http://www.summitracing.com/parts/WVI-30-5734042/


So if I buy these rims, what size tire do you guys recommend I go with? I ram running the generic tri5 disc brake kit with the 2" drop spindles. I just want the overall best size tire that matches my car and provides a nice even stance. I don't care if it's a 26/27/28" tire as long as it will look and fit the best. I figured out why my car isn't resting where it should... long story short I am an idiot and the body is sitting on the tires via the pinch welds by the inner wheelwell. Once I open it up and add the mini tub I will have plenty of clearance. We only threw on the rear tires to verify we welded the purches in the right places and to verify everything bolts up and fits like it should and we didn't realize the body was resting on the tires until tonight. I am not sure how much further it will go down once we open it but I am hoping at least 1-2" .. Anyone have a pic of a stock rear suspension setup with a 1" block?

Thanks for all the help guys.. Now I am back to my original question for the best sized front tire / rim..I will order what you all think will fit and look the best.. Tires/wheel fitment is not my area so that's why I need help from pepole that's already been there. Thanks again for everything. Once this is done I can start the fun stuff. wiring and installing my new 1000+ hp power plant ( which is the type of thing I know how to do ) Thanks again!

Maybe one of these tires? Will any of them fit well on my current rims 7" rims with 4" bs? If not I don't mind buying the 4.5" BS ones.

http://www.summitracing.com/parts/KUM-1908513/

http://www.summitracing.com/parts/MTT-6025/

http://www.summitracing.com/parts/KUM-1908013/

 

[Chevynut]

I am in luck.. I plan on running rallye rims on my car and they make a 7" with 4.5" BS rally rim and it's not very expensive. I am sure I can sell my current 4" backspacing rims without a problem if I need to switch rims.

http://www.summitracing.com/parts/WVI-30-5734042/


So if I buy these rims, what size tire do you guys recommend I go with? I ram running the generic tri5 disc brake kit with the 2" drop spindles. I just want the overall best size tire that matches my car and provides a nice even stance. I don't care if it's a 26/27/28" tire as long as it will look and fit the best.

I'm not sure what you mean by "fits the best". The tire diameter doesn't necessarily change with the tire width. Are you trying to get a tall tire on it, or a wide tire? Do you want a tire similar to stock height? I personally wouldn't go much under 25-26" diameter or it starts to look weird imo, unless you lower it a lot in front.

If you want a reasonably wide tire that's close to stock height, go with a 225/70-15 (27.4") or a 225/75-15 (28.3"). Some people go as small as a 225/60 tire (25.6") and imo that's getting on the short end. There are lots of choices depending on your taste.

A 225 tire on a zero offset wheel (7" w/4" BS)will give you a front end width of about 68.1". A 4.5 BS will make that 67.1". I think either wheel will work with your 2" dropped front end.

I figured out why my car isn't resting where it should... long story short I am an idiot and the body is sitting on the tires via the pench welds by the inner wheelwell.

That 'splains it!!

I am not sure how much further it will go down once we open it but I am hoping at least 1-2" ..

I think it will be at least that, probably more.

There are lots of posts here where people show their tires. Try a search.

 

[56RAT]

I'm not sure what you mean by "fits the best".
If you want a reasonably wide tire that's close to stock height, go with a 225/70-15 (27.4") or a 225/75-15 (28.3").


I think it will be at least that, probably more.

There are lots of posts here where people show their tires. Try a search.

Will do. Still new here but I am slowly getting the hang of it. Thank you for the quick replies. I think I will give the 225/75/15 tires a try, With the lowered rear and the 2" drop up front I think those front tires will give me the look I want.. You guys are great and I am happy to be here and hopefully I wont be asking any more questions for awhile. I have learned a lot on this site so far by browsing around and I wont ask any more questions unless I search for 30 minutes without any luck.


I can't wait to see how it actually looks when it's sitting down without rubbing in the rear. Hopefully this weekend! it's going to look great, I can already tell.

 

[56RAT]

The Mystery Continues

we completely cut out the tubs and the tires are not touching the frame or body anywhere and the car still sits high. We have no idea why but that's the way it is. Nothing is interfearing and nothing is touching or out of place. Only thing I can come up with is the fact the new tires are way taller than the old ones.. I think the leafs are new as well ( within 2-3 years ) as they still seem stiff and they don't seem like they have sagged at all like original ones would..

We used the original springs. The only thing we changed was the pocket kit , caltrax , taller tires and the 1" block of course.. I even removed the caltrax just to see if that was the problem and it's not. Obviously that's where it's going to sit so my only option is to lower it more.

I want to drop my car 3" from where it sits, So what do you guys suggest I do? I can buy 2-3-4" lowering blocks but I heard it's not a good thing to do with a lot of power under the hood due to the leaf spring geometry in relation to the axle, it causes problems with launching.. Is this true or is it just a myth? I will be running 1000 Horse in this car. WHat do you suggest I do? My 3 options as I see them are:

2-3" block above my 1" that's already there.. ( cheapest and easiest option if it will work okay )

re-arch my current leaf springs (lowered 2-3") not sure how much this costs but I heard it can be done

buy new 3" rear lowering leaf springs ( do they even make 3" drop springs? )


Please let me know what you all suggest is the best and most effective way to lower the rear of my car. Thank you.

Nathan

 

[Chevynut]

There has to be a reason your car is sitting so high in the rear, if you're really using stock springs and a 1" lowering block. I'd figure that out before I did anything else.

Did you measure the distance between the top of the rear axle housing and the bottom of the frame hump? It's supposed to be 5.725" with a stock suspension. With the lowering block it should be 4.725". If it's more than that, there's something wrong or you don't have all the weight on the car.

 

[56RAT]

There has to be a reason your car is sitting so high in the rear, if you're really using stock springs and a 1" lowering block. I'd figure that out before I did anything else.

Did you measure the distance between the top of the rear axle housing and the bottom of the frame hump? It's supposed to be 5.725" with a stock suspension. With the lowering block it should be 4.725". If it's more than that, there's something wrong or you don't have all the weight on the car.

I will measure tomorrow and post the results. For all I know they are stock replacement springs. I can tell they are not the original 1956 springs but they were already in the car when I purchased it and I can tell they are somewhat new.

I rolled the car tonight and even sat in the trunk and bounced up and down and the car has all the normal suspension travel in it. It's not hitting or binding / rubbing on anything and I checked both rear tires for any obstructions.

I will post the #s tomorrow. thanks for the reply. I just don't understand how anything can be installed wrong. the leaf springs only fit one way..

 

[56RAT]

anyone here used these springs before? They look to be pretty nice and I like how they move the rear end 3/4" back for use of bigger tires with a more centered look.


http://www.classicchevy.com/chevy-5-leaf-rear-spring-offset-2-lowering-1955-1957.html

http://www.classicchevy.com/assets/pdf/classicchevy/21-262.pdf

 

[Old Buzzard]

Did you torque the rear shackle bolts w/ the weight off of rear??
Did you lube the front bushings on the Cals b4 U installed them?
Does the ft edge of the Cal bracket hit the ft of the pocket?
Does the Cal brkt slip into the pocket, freely?

 

[56RAT]

There has to be a reason your car is sitting so high in the rear, if you're really using stock springs and a 1" lowering block. I'd figure that out before I did anything else.

Did you measure the distance between the top of the rear axle housing and the bottom of the frame hump? It's supposed to be 5.725" with a stock suspension. With the lowering block it should be 4.725". If it's more than that, there's something wrong or you don't have all the weight on the car.

My car is at my buddies house and I just called him and had him measure from the top of the housing to the bottom of the frame hump and now I am even more confused :confused0024:...

If he is measuring in the right place it's about 8 1/2 - 9 inches. I don't understand how this is even possible, if you are saying it's supposed to be 4.725" and we are at 8" that means we are not even in the same ballpark. I want my car to sit about 3" lower than it is now which means it " should " already be there.. :frown:

We installed everything by the instructions. I can take pics of everything tonight if you would like. Everything went together well, we used the grease where it said to use it and the cal tracks moves freely in the pockets and they are not binding up at all. We didn't have to pry or bang on the springs to get them in the shackles so I don't feel like the springs are tweaked. We rolled the car, jumped in the trunk and it has full suspension travel just like it should. We tried it with the caltrax bar connected and disconnected.. Is there any aftermarket springs that actually raises the car? I wonder if the previous owner put in some springs that raises the ride height? could this be a possibility? the springs look newish.. 3-4 years old is my guess..

Moving the springs into the frame rail doesn't change the ride height does it? I assume it's supposed to keep it right where it was? Is there a possibility the shackles are on backwards? They looked to be exactly the same so we just threw them on. Even the original shocks fit exactly like it did before with the old rear axle in the car. I am 100% positive the tires are not touching the frame or body anywhere. We completely cut out the wheel tubs and the tires have full clearance all around and the car rolls without a problem.