I tried searching this but couldn't find it. What size are the EGR bolts on the 806 heads from a 98 Z? I'm pretty sure they're metric.

 

EGR bolts?? On HEADS? The only EGR setups on LS engines I've seen were attached to the manifolds (intake and exhaust).

 

Actually I think its part of the AIR system. The bracket bolted onto the front of the passenger side head in this picture. I'm mounting a catch can and need the correct bolts.

 

Everything on GM vehicles and engines is metric.

 

Yeh like I said I was fairly certain they're metric. I just don't know the size. I've pilfered through every bolt in my tool box but can't find one that fits. The hole is about an inch deep. Just don't know the thread size.

 

Should be M10x1.5, about 30mm long IIRC

 

Well, since the late '80s and into the '90s, depending on the engine.
Gen I & II engines used all standard measurements, but the vehicles they were installed in often had metric measurements.

Ex: Third and 4th gen F-bodies, GMT 400 trucks, and GMT 600 vans.

If there's one thing I hate, HATE, HATE, it's morons who can't tell the difference between metric and standard, and round-off bolts, ruin threads, etc.

Those guys should have their tools taken away, and be put to work mopping the floors for real mechanics.

 

Thanks man.