Has anyone replaced a flat head 6 with a slant 6 in a 1958 d100? What problems can I expect? Thanks, Lew

 

You'll need to swap transmissions, make up some custom motor mounts, transmission mount/cross member, drive shaft, radiator inlet/outlet may be different and wiring (should be pretty simple though).

If you are going to be swapping to a slant 6, swapping in a small block V8 would probably be the same amount of work and you'll gain more power.

 

Thanks for the help! I already have a rebuilt slant6 with a 4 spd tranny. I will wait until a find a d100 with a bad slant 6. Thanks again, Lew

 

That is the easiest and cheapest thing to do with that /6. If the tail house length is short, you could also throw that setup into an A-body car with a /6 and have some fun too.