What header bolts are you guys using? What size are they?

 

I went with the ARP studs. They are expensive, but there are so many who have had problems with bolts that I think it was worth it. You have full thread engagement in the head prior to starting the nuts on the threads so the risk to the aluminum head is real low compared to using the bolts and risking a cross thread. Just my $0.02

 

used the bolts that came with my dynatech supermaxx system. Work just fine

 

Well I bought some used headers so, I don't have that luxury.

I'll check into those studs

 

I have Kook's LTs and used the original stock manifold bolts. Torqued them to spec at installation and then checked them after a few heat/cool cycles. No problems or leaks.

I used the stock metal gaskets as well

 

Stock bolts, stock gaskets and anti-seize. Five years with no issues.

 

I like that even better.

 

If your using factory steel gaskets (highly recommended) the factory bolts work very well. In the old days with paper/fiber type gaskets as they aged they would move around under the headers and compress causing the header bolts to become loose. Once they start to loosen the gasket will start to leak and once that happened it was not long it would blow out and you had to replace them. Locking the header bolts helped but didn't totally solve the problem. The factory GM gaskets are steel and will not compress any more after they are tightened. Just be sure you use the older round port gaskets and not the newer oval port gaskets. Order a set for a 99 C5 coupe and you will get the correct gaskets. You can normally reuse the gaskets as long as you don't damage them. Just make sure the ports in the gasket are perfectly round, not oval. Many people have used the oval gaskets and many have not had problems, but they don't fit the headers as well as the round port gaskets.

Just to be sure my bolts didn't come out, I bought the stainless Breslin bolts. They work very slick. Just be sure no one tries to turn them out without loosening the center pin first!

 

Good to know. I'll look at my stock ones when I take them out.

By the way, It is a 99 C5 lol

 

Stock bolts, F-body gaskets, LG Pro's no issues or leaks and a daily driver and driven hard.