4.0 ohv header bolt size?

[mobile madness]

I know I need 8mm 1.25 but idk the length. If possible id like to get hex heads. What's everybody gone with?

 

[94Reborn]

I went with a set from summit racing, they are actually for a corvette LT1 I believe. When I called their parts guy, he suggested them. I forget the length, but I believe they were just over an inch, 1 1/8 maybe. They are hex head. If you call their 1-800 number they should be able to tell you, I just called and told him the thread pitch and that they were just over an inch and he pulled those up for me. They worked perfect. Most header sets should come with bolts though, I know my hedman set did.

 

[mobile madness]

I got hardware but the sheet said to re use the stock manifold bolts so ehf that. But thx.