Yea i got the lm7 and lm4 backwards, point was he has a lm4 or lm7 (5.3) and not a Lq motor(6ltr).They are all in the ls family and parts enterchange.evildky wrote:sorry, LM7 is the 5.3 iron blockLM4 is the aluminum versionthe LM7 is in most 99-07 trucksnone of the LS motors came in the truckshttp://en.wikipedia.org/wiki/GM_Vortec_engine#5300