(Tounge-In-Cheek b4 ne1 cops a mental.) All silliness aside, you can definately direct mount a 7.4 to a 7X B/W. My question is though, that in this day of gas prices as they are combined with the idea they are going up from here and not down, why would you want to push a tri around with 7 1/2 litre gasoline driven V-8's? Torque for wheel pitch? Nowai. Thats broken logic as I see it, sorry for saying so.
If you are talking reasonably about repowering a tri-cabin in todays world, then resonably you have to take big blocks out of the equation. There is really no need to have them if you are going to already go to the expense of doing a proper refit when you consider the changes in marine engine technology since the glory days of Trojan production. The torque curves on modern small blocks blow away what was thought of as cutting edge in the 70's. If you have to go gasoline then IMO you have to go GM small block to repower one of these in todays world. Call me crazy, but thats the way I see it.
Alternatively, I'd try to think of a way to get a 4.3 Vortec V-6 to work in an F-series. Theres an idea which defys convention, but I think Scott is already ahead of the curve using 6 holers in an F-32. His are the trusty 165 inline jobbers which are period correct but never a factory option, but considering the results hes been getting (which from what I've heard about are pretty darned good), I'd really be interested in what a modern 4.3 could be made to do in this application.
