LS5 exhaust manifold bolts

[tom444634]

The dr side exhaust manifold on my 71 LS5 cracked at the #1 cyl mounting ear causing an exhaust leak. I was able to remove it without breaking any bolts (I took that as a sign that my Corvette really loves me!). When I go to replace the manifold (I located another correct one to replace it with) I wanted to put new bolts in.

The bolts I removed had built in washers for the #1 (except for the power steering / alternator bracket stud) and #7 cylinder. The bolts for the #3 and #5 cylinders are regular heads, not washered. The passenger side is the same also.

I ordered the "correct" bolt kit from Paragon and it does not have the washered bolts in it. Just 15 regular bolts (with the correct head markings) and the stud for the ps bracket.

So what is correct? The bolts I removed from the car, which I believe to be original, or the bolts from the kit I ordered?

Would it be safe (wise)to reuse the old bolts? (I think not, but I'm all ears)

Thanks

Tom

I can put some pictures up if any one is interested.

[lyndon sharpton]

Re: LS5 exhaust manifold bolts

let me see the bolts please. what month was you car built?

[Dick W.]

Re: LS5 exhaust manifold bolts

Tom, I would tend to agree that the bolts removed are of the correct style. If your old bolts are not rusty to the point that the diameter of the shank is reduced I would clean them up, use an anti-seeze on the threads and reinstall. Pay attention to the proper torque

[tom444634]

Re: LS5 exhaust manifold bolts

Lyndon,

The car was built in early September of 1970. Serial number 1632.

Pictures of bolts below.

The first one shows three bolts. The one on the left is the one with the built in washer which is on the outer cylinders on both sides. The one in the middle is the bolt used on the middle cylinders and the one on the right is the one from Paragon.

The second picture shows the PS stud. the larger bolt head was off of the car. the smaller one is from Paragon.

Tom

[tom444634]

Re: LS5 exhaust manifold bolts

picture number two

[Dick W.]

Re: LS5 exhaust manifold bolts

Tom, personally if the car were mine, I would get some metal etch(available at most auto paint stores) soak the bolts for a few hours, rinse, oil thouroughly, neverseize the threads and reuse them

[Joe L.]

Re: LS5 exhaust manifold bolts

Tom-----

The bolts for the end positions on both sides (i.e. #1, 2, 7, are special washer head, LOCKING style bolts. These bolts replaced the standard bolts with french locks used earlier and are 1-3/16" long. The length "compensates" for the thickness of the french locks since the machining of the manifold end bolt hole bosses remained unchanged even after the freench locks were eliminated. They are still available from GM under GM #3909821.

The remaining bolts are standard, hex head bolts of 1-1/4" length. They are available under GM #3736035.

The exceptions to the above are any positions where a special stud was used in place of a bolt. This includes power steering and A/C applications.