View Full Version : Big Block Mounting Issues
06-08-2007, 10:49 AM
Hey guys, I'm brand new to the site but had my car since 1988. It's a 55 Bel Air 2 dr hardtop with the original 265/3 speed. Since I graduated high school in 1984 and loved the pro street movement, I just had to create my own retro beast. I'm going to change the driveline completely and am running into some difficulties. I have a .030 over 454 with a Bowers 8-71 supercharger and am trying to figure out what type of engine mounts & headers to use. The problem everyone tells me is that the side mounts that move the engine forward will not clear the headers or allow them to be installed. I believe that there is no possible way that the blower would clear the firewall without moving the engine forward. The windshield wiper motor has been removed but there still looks to be interference issues. Also, my heads have been thoroughly massaged and I need at least a 2" primary header, preferably 2-1/4". I would even be willing to go to fenderwell headers since my front tires will be small. Any help and advice from people who have been down that road would be greatly appreciated.
06-08-2007, 10:56 AM
It is very rare for headers to interfere with side mounts. Steering box clearance is a much more serious problem - but it's usually not too affected by fore/aft placement of the engine.
Most guys move the engine forward 3/4" - 1" with a big block. As you think about this, make sure that you have a plan for everything to fit at the radiator end too, especially with a blower.
06-08-2007, 11:08 AM
Thanks for the quick reply Rick. Since I'm sort of "old-school", I'm not running any power steering and sticking with the original manual steering box (don't want to waste hp unnecessarily-lol). Any issues with header clearance with that box? If it's too much of a hassle, I would be willing to convert the box to a different type for clearance issues. Also, I had thought of running the Hooker Super Comp 2-1/4" primary headers but am unsure if they will pose any interference problems as well.
06-08-2007, 11:15 AM
Also, Rick I installed a six-cylinder mount years ago in preparation for running a supercharger but need to convert the Desert Cooler copper and brass radiator over to a more conventional cross-flow aluminum radiator. I'm hoping everything will clear the drive without having to hack up the radiator mount up too much. Any other suggestions would be appreciated if I'm going in the wrong direction as far as cooling this beast. One more note: I plan to later build a 540 or 572 with the same induction setup if that makes any difference.
06-08-2007, 11:17 AM
Welcome to the site from a fellow Texan. Good to have you here.
06-08-2007, 04:42 PM
Ive got a 55 that Im putting a blown big block in . Ive got Earle Williams headers , 3/4 forward side mounts , and I also bought an oil pan from him . His stuff just plain fits ! Some will chime in about the price , but as I said his stuff fits . The steering linkage is where most people run into problems with big blocks and headers , I dont think you will have a problem with the fire wall and the blower , but if your valve covers are too tall , you will have a problem, even at 3/4 forward I believe .
Another great thing about Earle , he will answer all your questions . Good luck Brother and welcome .
06-08-2007, 06:53 PM
Thanks Bulldogger, I'm a firm believer that you get what you pay for and if his stuff fits the first time out, then it's worth the extra expense. Thank you for the welcome as well. I'm glad to be in this brotherhood of shoeboxes mainly because I bought this car in '88 for the princely sum of $1500 (and I thought I might have overpayed!). Now, that money couldn't even buy a clapped out hull and I know I couldn't afford one at today's prices.
If anybody has further comments/advice, I'll take them. That's what's great about our hobby---if somebody takes a wrong turn in their resto, they're not afraid to help a fellow enthusiast avoid the same mistake. ;)
06-09-2007, 12:58 PM
I put a big block in my 56 some 7 years ago,one of the best pieces of advice I got was from S&S headers. They said to wait til I got the headers to install the motor mounts. It is truely amazing the difference being able to tweak things an 1/8th or a 1/4 made. No dimples or gouges in the pipes:D Best of luck with the install Steve
06-14-2007, 11:59 AM
We are running a blown540 in our 55. It's a tall deck Dart block and we moved the firewall back 4" for clearance for the valve covers. The motor is 3/4" forward and had minor clearance issues with the spal fans on the PRC radiator setup. If price is no object PRC sells a complete set up with core support and cross flow radiator and their setup cools our 1000hp motor with no problem. Our headers were custom made by KromerKraft....Dennis
06-14-2007, 01:05 PM
Thanks Dennis, you've got a hardcore '55 there. I wish you had a picture of the firewall so I could see the mods. Did you replace the remaining firewall with a smooth one? Also, why did you have to remove 4", was it due to the tall-deck block? - Russell
06-14-2007, 09:08 PM
maybe this will help? i was thinking this might be what i will use for my 502 crate motor. they have alot of stuff on this site check them out you shoud have enough clearance and you might want to call about the primary sizing best of luckhttp://www.classicchevy.com/product.asp?pf%5Fid=18%2D241&dept%5Fid=2208
06-14-2007, 09:51 PM
The classic chevy mounts that wills55 suggested is how I went. They fit real nice. Did not have to touch firewall. Can get a 2x2 behind HEI cap. Nice! Can pull dist and put back in in 5 minutes or less! Can go with tall vave covers no problem. I did not buy the whole kit though. I bought the full tube headers they offer, but thru Summit. They are a little different, but for 145.00 a bargain. The same ones jet coated were alot more. I bought the painted so I could bang on them! I will send them out for ceramics come winter for a quote of 250.00. I have many photos and have done this conversion since November. I will email por post any pics you want, just ask. Phil...
06-15-2007, 12:31 PM
Hi Russell, yes we set the fire wall back for a couple of reasons one being the tall deck and the other is the jessel rocker system and the tall valve covers. We had to move the MC as well. Send me an e-mail address and I'll send you some pics of the fire wall. Regards, Dennis
06-15-2007, 03:02 PM
Thanks guys for all of the suggestions/help. I looked at the Eckler's kit and it looked like a well thought out product but I'm afraid that the 2 1/4" offset would require a lot of work to get the blower's drive to clear the radiator & electric fan setup. One bonus is that I'm planning on running one of MSD's small diameter billet distributors to allow clearance of the blower and firewall, so, I hope I won't need too much offset. I bought a set of 3/4" offset sidemounts about 6 mos ago and was hoping that I could still use them. One thing for sure, I'm not mounting anything until I get my headers.
BTW-Do any of you guys still run the manual steering boxes? I plan on keeping mine and wondered if it has any bearing on header clearances.
06-15-2007, 05:58 PM
Hey ,I'm building a 57with a 871 in a 454 ,been working on it for about a year ,best I could do was to replace the stock steering with a flaming river rack .Like you I want the 2 1/4 headers and I couldn't see any way for enough clearance with the stock steering . I did some mods to the firewall to clear tall valve covers and offset the Master Cyl. My engine mounts set me at 3/4 forward I made my side mounts . The pan is a milidon 7 QT for a 57 and I still had to modify it in front to clear the steering . Have you thought about the rear end ? Hot Rodding is all about the solving the problems and having fun with it wish you luck just don't give up keep moving forward .JW
06-15-2007, 06:29 PM
I'm puttin in a 68 427 and my driverside header is a tight fit but it clears. I'm running solid motor mounts so I'm not too worried about bangin them up when the right foot gets a little heavy. The only other clearence problem is tall valve covers. They were close and I was smoothing the firewall any way so I went ahead and pocketed the sides. I've moved the motor forward 1" and had it in and out several times. Go for it! Just take your time and think before you do. Words of advice from my dad. Now we are doing his 56 but he's got the money and no problem with cutting the frame so we are doing a Fat Man frame stub on his.
06-16-2007, 12:19 AM
i dont know if the tubular core support that ecklers sells will give you anymore room but you could always take a look at it and see if the blower drive will clear the tubular one. just a suggestion
06-16-2007, 08:23 AM
Thanks for the input Jerry. Did you ever decide which headers you were going to run? Also, the rearend is completed and bulletproof: narrowed Ford 9", detroit locker, Moser axles, Comp ladder bars and Richmond 4:11 gears. :cool: I hate doing things twice and try to get it right the first time if possible.
Hey OneBad56, are you smoothing the firewall with a kit or just fab'ing it up yourself? I would love to smooth the firewall on mine but wondered how in the heck to work around the body support braces. Did you cover yours up or just leave them in place? I saw some pictures of you and your Dad's rides and you guys are gonna drop some jaws when you pull into the Sonic together! :eek:
Thanks for the additional info Wills55. I will check into that radiator support because I will have to hack my original up anyway to put in the crossflow radiator I plan to run.
06-17-2007, 11:52 AM
Check out the slideshow for pictures how we did mine. Jim
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