I have the cylinder heads off my '87 GT 2.8L, and need to have a small crack repaired on the rear exhaust manifold, before re-installing.
Are the stock exhaust manifolds made from mild steel, stainless, etc?

Also, the bolts for the exhaust manifolds are very rusty, and I would like to replace them.
Is the best replacement studs rather than bolts?
Any known source and/or part numbers for exhaust manifold fasteners?

Thanks for the info.

Hi,
The manifolds are stainless - youre better off while there off the head porting them (many topics on this forum)
M8 threads and yes you can get a stud kit off ebay I think fierojon supplied mine - there better than the standard bolt set up as you have probably seen on the forum about broken bolts in the cylinder head and what a pain to remove them.

hope this helps
jon

The manifolds are a high alloy steel (not sure they would be termed' stainless' but the effect is similar). There is no problem welding them.

You can buy a new stud set from the Fiero Store.

The 1988 modesl had the holes in the flange ovalled a tad to prevent cracking and stud breakage from expansion - that's something you could do to the manifolds while they are out if you like.

Get the correct pitch for M8 which bolts which is 1.25 pitch and use lots of antisezze

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if you have a junk yard near by with lots of saturns they use the same studs and bolts.

Yes, that is a Saturn stud kit, seen them on eBay, Fiero Store has them too.

Just in case, here is my exhaust manifold gasket replacement thread chock full of part numbers, tips, hints, pictures, scraped knuckles, cuss words and a wrench that got thrown against a wall.

https://www.fiero.nl/forum/A...120111-2-065384.html

Good luck with the rebuilding project!

Thank you for all the info.

Any idea what year and model/motor the Saturn stud kit is made for?

After soaking all the exhaust manifold bolts for a day with PB Blaster, I was able to remove all today after work, with the exception of breaking only one, which I will drill out tomorrow.

The reason I took the heads off was that I had a bad 'miss fire' in cylinder #6, with oil that had gotten into the antifreeze. I did the tear down, expecting to find a bad front head gasket blown at #6 cylinder. When I took the intake manifold off, I found a bad intake to cylinder head gasket on the front head above the #6 cylinder. I figured that was probably the problem, but as long as I had it torn down that far, I figure I would check the head gaskets too. They both looked good, but still glad I went the extra mile to take care of a few more items just to be sure.

[This message has been edited by hdryder (edited 03-14-2012).]

The manifolds are 409 stainless.

Studs are good for the front side of the engine, as they make it easier to hang a gasket on them, then slide the manifold into place. I personally am not a fan of studs for exaust use, as they have two potential modes of loosening up.

Anti-sieze, anti-sieze, anti-sieze. Don't forget the anti-sieze!

So M8 x 1.25 x 50, stainless, or heat treated, 10.9 or better?