the link i posted in my 1st post on this thread is a forum dedicated to 6bt cummins engines like this forum we on dedicated to A bodys!! it has lots of useful info on the different models of 6bts and what parts work best!! liston to Dukeboy_318 on the killer dowl pin cause it will kill a 6bt quick! and he right gaskets only use cummins head gaskets!! the aftermarket rebuild kits are fine just dont use there head sets, but cummins premium+ parts are the best! 4bt and 6bt engine some of the best cummins ever built, alot better than needed in a pick up truck!!