I was having a discussion with a friend of mine and he said LT1's are 2 bolt mains, where I was certain they were 4 bolt. So, I thought this was the best place to come and find out. It is a 2 or 4 bolt main or did they design both? Thanks for the help!

 

They are both[and unfortunately you're not able to tell from outside...]
Vettes and replacement blocks are 4 bolt .. the rest are 2 bolt mains..

 

All lt1 vettes are 4 bolts. F-body and B-bodys are 2 bolt. And chances are if you got your shortblock replaced under warranty you now have a 4 bolt.

 

That's interesting, my LT1 was replaced under warrenty because of engine knock and low oil pressure... I wonder if it's a 4-bolt main Either way, 2-bolt mains hold up fine.

 

Thanks for the info, much appreciated. It turns out we were both right.......lol.

 

My engine was replaced under warranty also, about 60K on it now. Does that mean that mine is also a 4-bolt?

 

Replacement LT1s are 4-bolt as already mentioned.

 

4-bolt? Thats good to know! I guess I should say thanks GM.