LOL.... don't give away my secrets to success!!!! :D
I may use the 360 already in the one Duster. If so, then that will be the one that weighed 3240.
If I put together the 360 I saved from the scrap yard, then I'll probably put that in the 318 Duster, which weighs 3160.
Either way, I'll be changing rear ends and adding headers.