The jeep 4.0 inline 6 is another possibility. The engine design goes back to the sixties AMC 232.
A Tampa outfit is selling thru quadratec 4.6 stroker long blocks with 260 hp and 295 fp torque.
Hmm, 260 crank hp is a bit light in terms of target, and there is no practical opportunity with this solution for future building up to get more. I think I want either more right now, or at least the opportunity to get more later, if I am going to go to the trouble of engineering the engine swap!
Jim G