I run a 1975 IH 200 pickup. I run a dana 44 in the front and a 14 bolt in the rear. When I bought it, it had a 427 tall deck in it. It ran really well. So well they threw us out for running a cheby. Make and manufacturer now have to be the same. For power now we run an IH MV446 motor out of a dump truck. The motor we ran last year was box stock. 235 horse, gobs of torque. It is only a 3600 rpm motor though. It'll top out at 4400rpms pulling the sled. 4600rpms flat out down the street. We were having a motor built last year to run up to 6000 rpms. Only to find out that the motor guy was building parts for me and selling them to others. He also sold some stuff off my motor.
I have a block done now, cut 40 over and will run 10 to 1 compression instead of 8to1. I need a cam made. Found a guy to make my cam and found another guy to do some head work. BBC valves and springs to let it breathe. An intake off a 460 lays out the same space wise but is 1 inch too narrow. So.. spacers will have to be made for this. Seems like alot of trouble to run an IH?? Just a hobby and a challenge. There are NO aftermarket parts made for these.
This will most likely become a long term project and I will try and get the 78 F250 on a 4X4 running gear. Horsepower will come much cheaper.
There are guys out here spending 6 to 8 grand on their "stock" truck engines. Word is there will be a 460 running over 600 horse this year. Some 454s are there now. Cast iron intakes. There are pics in my album.