New k10 4x4 help

[70k10fourby]

Hi guys. I've been an old car guy for a while but recently sold my newer Silverado and bought a 1970 k-10 4x4. Tired of paying high registration and insurance and smog in California, and buying vehicles that just depreciate. I found a nice truck, original paint, great body with factory A/C. I've got some questions about the motor that would be right for this truck to be my daily driver that i offroad on the weekends. I need it to get good mileage but still be fun to drive. It's got a 3/4 drive train, 60 in the back and 44 in front. 4.10 gears and 33's, and an np205. It had a built 350/th350 that i just yanked out. I bought a 700r4 for it and am researching motor stuff right now. A friend has a tpi 305 out of a 1990 IROC camaro that is brand new (has 200 miles on it before car was totaled.) Would this be a good motor for my truck. I know these made a lot of torque. Or should i spend some cash and builder a nice 350 to do just what i want. Any thoughts would help, thanks.