I wanna put a iron block in my car but not to sure what the differences are between the lq4 and lq9 if any??? I thought that the heads were different but whats different about the short blocks??? Thanks!!!

 

LQ4 has dished piston with compression ratio of 9.4:1 and LQ9 has flat top piston with compression ratio of 10:1. LQ9 is supposed to have better rods and pistons. They both should have the same 317 casting number heads which are just a larger combustion chambered version of the LS6 heads. Bare blocks are the same.

 

Ok really i just wanted to make sure the blocks were the same... And i planned on running the 317 head with a good forged rotater with boost so i wanted to make sure on the blocks!! I found a 60k lq4 block only for $150 so i didnt wanna buy it without knowing... Thanks!!

 

How do you like that sts kit?? You make decent power with it?? Whats done to your motor??

 

PM sent.

 

Exactly whahe said...

 

Yes LQ4's have lower compression due to dished pistons and the LQ9 has flat-top pistons yielding a higher compression ratio. Heads are the same 317 casting for both.