jeez i didnt even bother to check or really how to check

2 bolt main block or 4 bolt main block for the lt1s i guess are the two.. how do i tell which i have--- when i bought the block new it had cast iron heads on it , so it prolly came out of a impala , roadmaster, or something like that... how do i check now that its in the car? and i hear 2 bolts arent the greatest =/ hopes for the best ;p

 

i dont even know if it came out of one of those, but what i meant to say is that it's the motor that was used in those cars prolly, because the block is like brand new, seemed only to be started once to check if it was good, everything is perfect.

 

It's most certainly a 2 bolt block if it came out of an Impala or Roadmaster and had iron heads. All Fbody LT1's were 2 bolt blocks with the exception of around 129 1997 LT4 cars. All Corvette LT1's came with 4bolt mains though. Are you sure you got an LT1 though? Some of those cars you mentioned came with the L99 4.3 V8 which looks just like the LT1, some call it the "baby" LT1. If it's out of an Impala SS it would be a LT1 with iron heads, but I think a lot of regular Imps, Caprices and Roadmasters had the L99, not positive though.

 

its certainly a lt1, it says 5.7 on it, and everything else matches specs... but ya 5.7 is stamped on the block.

 

Whats the casting number off of the back of the block? Look at the flange where the tranny bolts it, and there should be a 7 or 8 digit number. I can't remember which. You can tell what you have from that.