[Joe67]

Originally Posted by FirstGen

All this information is good however the LQ4 and LQ9 are identical motors less the pistons. The heads are the same (317 castings). For some reason alot of the published books have this information incorrect. The only 6.0 that had iron heads was the pre- 2001 motors. The actual difference in the LQ4 and LQ9 is the LQ9 has a true flat top piston (hyper) and the LQ4 has a small dish (also hyper). EVERYTHING else is the same. The books even list different head numbers but this is a phantom head as I have yet to see one. Basically if you get an LQ4, shave the heads a little and you have a LQ9 - or leave it and run a blower! LQ4 = 9.4:1 CR and LQ9 = 10.2:1

I was unaware current LQ4 motors have aluminum heads, that is a good thing.

Here is a link to the current Vortec motor specs

http://media.gm.com/division/2005_pr...ine_specs.html