Diff in years for LQ9
-The LQ4 is the low compression motor used in 2500HD trucks, express vans etc etc... Dished pistons, 9.5:1 comp.
-The LQ9 is the motor used in the SSS's, Escalades, and VHO's. Higher stock comp ratio... They both share the same BLOCK. Pistons were the only difference.
The only difference is the head bolt length as stated. No difference in bolt pattern.


