I'm putting headers on my truck and I had to cut the nuts off of the factory studs to get the manifolds off. I can't find new studs anywhere and can't find a bolt to fit them. They're not the same as the bolts, anybody know what they are?

 

This is what I used.
http://www.summitracing.com/parts/stg-8955

They're 5/16"-18 x 1" long... all the same.

 

My headers came with 8 5/16-18 bolts and none of them will thread into the stud holes? They go into the others just fine though. I've tried them, 8mm 1.25 pitch, 5/16-24 and nothin goes in any of them for some reason. Might just have to cram the 5/16 18s in

 

If new bolts wont go in with relative ease, then the thread needs to be cleaned out.
Use a thread chaser, a bottoming tap, or a bolt with an axial groove cut in it.
Work it in and out a little at a time, and blow the crud out so it doesn't bind up.