Z28 exhaust manifold crack opinion

[KevinW]

Originally Posted by rszmjt

Chances are you will have to drill the bolt holes out a little bigger on the end cylinders #1 & #7 anyway, those style manifolds always seem to shrink in from heat.

We used to see that sort of cracking on similar design exhaust manifolds from mid 70,s Chev trucks that had propane conversions.

Thanks for the tip. I will test fit the manifolds and see how they fit before welding. I can always hit the bolt hole with a die grinder.

[rszmjt]

Originally Posted by KevinW

Thanks for the tip. I will test fit the manifolds and see how they fit before welding. I can always hit the bolt hole with a die grinder.

Very hard to die grind that length of hole, just use numbered bits and drill it slightly larger till bolts go in if the manifold has shrunk.