wiring harness....engine swap

if i was to swap out my 3.1L for a 3.4LDOHC, or L67, is there a place a can get a wiring harness like conversion, or what would I do? is there something i can plug into my 3.1 harness to work for those motors, if anyone could tell me it would be greatly appreciated. thx

www.L67swap.com

Those guys should be able to help you out.

Im pretty sure that they just swap the whole deal.
motor/trans/harness/pcm

I checked the site and L67 changed a lot since the 3.1 engine. I think the 3.4 DOHC would be easier to do than the L67