just got done installing a new oil pump on my ls1...followed all the tips and instructions for the install.is it safe to fire the engine without the timing cover and pulley on to make sure the o-ring is not pinched or anything..trying to avoid buttoning it back up in case the oring has a problem........

 

sure but don't drive it it that way.

 

cool....and would a oring problem show its face immediately upon firing?

 

ttt...........

 

I doubt it would be noticeable as far as a leak goes.

 

No. At start up, you'll have high oil pressure because the oil is still thick/cold. You'll know your O ring is pinched when the OP reading drops dramatically when it gets warmer/hot and the oil gets thinner therefore it'll bypass the O ring seal "if" its pinched.