from what i've heard, the 2nd gen 3sgte is the best engine to mod. i think the 3rd gen 3sgte is map sensored too. if you wanted, you could just plug in a jdm 3sgte ecu and rewire the egr system (if you even have to do that..) and you'd gain like 20whp.

but yeah, the 3rd gen is a straight drop.. you'd just have to get a new wiring harness and stuffs. just go with the rebuild!