the studs are for use with a fan clutch assy. remove the studs and get 5/16" bolts 3/4" long with a flat and a lock washer for each bolt and install. make sure to get the same thread as the pump end of the stud.

 

Thank you so much!! I was like what am I doing wrong here??!!

 

Isn't there a centering pin on the front of most water pumps? Maybe I'm imaging that?

Anyway...I had some chrome pulleys on my motor a long time ago and had the same problem. We put them on my pop's dial indicator an they were way out of round. They went in the trash and I bought some March pulleys (which were also slightly out of round, nothing major, but it's handy to have a Bridgeport lathe on hand too!).

Hopefully yours aren't out of round.

 

There is a pin in the middle from the pump, but the current studs don't tighten down enough to mate the pulley up snugly against the pump. It did hit me this AM though that the fan blade will in fact have to go on there, so now I'm back to washers etc.

 

Can you remove and thread them down some?

 

I have totally figured out my moment of stupidity..

The fan blade, once installed, will snug the pulley up to the pump. The only thing I've noticed is, the fan blade that I have is, I *think*, a '57 fan blade, where the engine is from a 1977 Camaro. That said, the studs that I had on the engine to connect the fan blade, and pulley, to the pump with, are not long enough to do so (ie the studs, when fed through the fan blade housing, are the same length as the area/hole where the studs pass through).

That said, I think I will follow the lead provided by 726, and get new bolts that are slightly longer, to accommodate the old blade and the new engine.

I haven't gotten to work on an engine like this in over 10 years, so I'm trying to dig back in my skull to all of these little details I've forgotten about along the way! I used to have a 1966 Chevelle with a 327 in it, and I was on the Chevelle mailing list if anyone here was on that list as well.

 

just wait until you get to the whole host of other fitment issues you will have using a long pump in a trifive truck. the short pump is a much better choice.

 

It’s a good idea to leave a couple of those short studs in the water pump hub to help line-up the holes in the pulley and fan to ease starting your first new longer bolts.

I think they are 5/16-24 about 3/4 inch long.

 

Not sure how I'm messing this one up..

Took one of the studs to HD. Waited in line for 15 min just to enter the store. When I put a 5/16 nut on the stud to confirm its threading, it wouldn't screw on. The local helper sees me and offers to help. He identifies the stud as metric, not SAE. I buy bolts and bring them home. They won't thread into the water pump. @#$@#)$(!)@#!@. Maybe it's time for a beer, lol.

 

Did you get coarse or fine thread?....I believe they are fine threaded bolts/studs

 

Lol. This stupid virus thing has me all jacked up. Maybe I'll venture out again later this evening. I did at least get my pipe plugs for my intake and water pump though!

 

Lowe's had the bolts, and yes, they are fine thread 5/16".

 

It’s not likely the water pump hub is out of line. They are machined flat and square and pressed on the shaft.

Water pump hubs are tapped for SAE 5/16-24 fine thread (not metric). Like I said, the bolts should be SAE 5/16-24 (not metric) about 3/4-inch long and at least a Grade 5. Use flat and lock washers.

If you tried to screw a course thread nut (5/16-18) on one of the studs, it will not run. Only a fine thread nut (5/16-24) will run.

 

We unfortunately don't have an Ace hardware near us, the closest are HD or Lowe's. I can't stand Lowe's but had no choice. I also go virtually no where now bc of COVID.

The new bolts are 1.5" long, they didn't have a 1". I'm going to test fit them but think they will be ok since I am adding flat and lock washers.

 

1.5 is way too long and will bind against the cast behind the pulley flange. I gave you the size in the earlier post. 3/4" long is all you need.
do you have a regular auto part store they will have what you need.

 

The studs on my pumps are like these. NAPA and most parts stores should have something like these hanging on a rack

Water Pump Pulley Stud Kit

OP needs to measure thickness of his pulley hub, clutch and fan (if used) to determine the proper length for his application. Like others have said go to an auto parts store.

 

I have taken pics of my scenario. Maybe the fan I have isn't a trifive, but if you look at the pics, after the 1.5" bolt goes through the fan housing, there's only about .25" left to go through the pulley and into the water pump. I think these bolts are going to work fine.

 

That fan looks like it has a 1/2" spacer on it...You could probably knock it off with one swift blow from a hammer....What engine is this going on? Is the radiator in the V8 or six cylinder position?

Also, I would try not use that four blade fan to cool your 350....Get a Derale Rigid six blade:https://www.summitracing.com/parts/...17317?seid=srese1&gclid=EAIaIQobChMI096ElYbk5wIVi5-zCh0F_QMBEAQYBSABEgKqTvD_BwE

 

Thanks!

I'll post a pic of the radiator location when I get a chance.

 

its a truck not a car.

 

Doh!

 

Also, I would try not use that four blade fan to cool your 350....Get a Derale Rigid six blade:https://www.summitracing.com/parts/d...SABEgKqTvD_BwE

This^^^.