383 440 swap. Same flywheel?

I consulted with my mechanical engineer friend at work on this to get a second opinion on the porosity of cast. He was of the opinion that any transfer of oil shouldn’t be enough to cause concern and suggested glyptal as a prophylactic measure, just in case.
So that is what I’ll do since with the present planned installation, the hole is not to be use for a pilot bushing and the input shaft will not touch it
In theory. The hole is 7/8 and the shaft is ¾.

In future, I’m thinking that even if I use a pilot bushing with glyptal sealing the bottom, perhaps having a little oil seepage for the sintered brass bushing might not hurt. (Tongue in cheek here)

But the question comes to my mind.
Does this mean that a cast crank can not be used with a 4 speed?
Other than a shortened imput shaft how did the factory do it?
Or did they not do it?
If I had to guess, is that what the register bushing/bearing was invented for?