ok this is a going thing with me i know but what would be the fastist swap in to my car and cheapis to get say 500rwhp in the end i want to keep the ac cuse this is a daly driver and with ok mpg say 15 highway

3500 would be better. The 3900 has a variable plenum and vvt so you would have to find a way to disable both. I'd say grab a salvaged 3500, put a big *** turbo on and let 'er rip!

I don't get why everyone says that about swapping a 3900, I imagine it would be no harder to just retain those advancements by swapping the ecm.

i should have sed 3.8 gn motor my bad

http://www.aaperformance.org/

http://www.taperformance.com/index.asp

It's not that simple either. There's multiple computers the ecm expects to communicate with. BCM, airbag module, instrumentation ect.