Ford made the 386 series engine in the 370, 427, and the 460. For heavy duty applications they modified the 370 and the 427 with beefier parts and harder lifters and valves I think.
The bell housings are still the same so you are able to swap in a 460.
My bus originally had the 2 barrel 370 and although I looked into getting a 460 I ended up sourcing out a 427 that I installed with a 4 barrell on it.
Now if I could only find the time to swap in a different rear end.....