Yes Frank, your 3.5 can be bored out to either 3.9 or 4.2. If you are going to do this, then the 4.2 would be my choice. I don't know of anyone doing an adapter for a 5L Ford motor but you might try..
http://www.marks4wd.com/rrovauto.html. Personally, I'd rather fit a Chevy LS1 5.7L mated to a 6L80E auto trans.
