The Pinto was designed for a four cylinder engine. The MII was beefed up a tad to carry a small V8, but did you ever drive one down a bad road? They are a pig! A buddy was nearly killed when his V6 MII flipped end-over-end on a straight gravel road. If you never go out of town, you might make it work, but drive carefully, the life you save might be mine!
The "suppliers" make kits for a lot of setups that are iffy, to say the least. I've seen guys replace much better front ends with a swap, just to be able to put MII on their list of mods at shows, things like '65 Coronets and '64 Galaxies.