My suggestion would be to pick up a donor vehicle - Suburban or 2500/3500 pickup with a big block. This way you get all the accessories. Lots of them out there cheap. More than adequate power for a big truck.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine