All,

How can one determine if the long block is a LS1 or LS6 if we don't know the orginial origin of the block. We don't have the Computer or intake. Is there any other way to determine this. What I can tell. Below the intake has the cover with the LS6 PCV system and it has the batwing design oil pan. How can I determine what this block came from?

Thanks in advance

 

I was told it came from a 2001 Pontiac WS6 but it had the wrong pan and PCV system

 

I was told that 241 casted on the head = LS1 and 243 casting for LS6

 

yes the casting numbers like you said are true. but a few ls1 camaro and t/a came from the factory with 243 heads. look around on the block for a part number i wanna say its on the drivers side towards the front but im not for sure, then run that number through the search and you should come up with wether its an ls1 or ls6.

 

Yes and no.

Any 243 castings coming from the factory on a Z or TA is a Myth. However, a lot of them DID come with an LS6 block (same strength, better oiling) so you won't know if the long block is an LS6 or LS1 by the block number.

243 heads = LS6
LS6 block = LS6 OR LS1

The performance difference between the 2 engines is in the top end (heads/cam/intake).

You can check the number on the intake to see if it's an LS1 or LS6 (though if it does not have EGR provisions it is an LS6)

The cam you can't really check in the engine.

 

i disagree with u about 243's being a myth unless you were there for every assembly.

ok your right about not being a different block number. still doesnt make sence why it wouldnt be different

ls6 has a higher lift more aggresive cam, higher compression pistons, and higher rate valve springs are a few significant differences. so you could degree the cam but that only works if u believe its not just an ls1 with the ls6 cam.