No, the bellhousing is part of the main case. Each 727 trans has it's own case. IE: slant six, small block, big block.
The easiest way to solve the problem would be to have a crank adapter/spacer made. It is a simple piece, and shouldnt cost much.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

So does the starter position make this engine and transmission impossible to mate??

No. just check to see what size crank adapter is in there now. Depending on what is there, either use that one, or have a new one made, with the correct size for the crank.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Crank pocket sizing was last weeks worry. Now I don't understand where the starter is going to fit when the location for it on the rebuilt ('65) engine is 4 inches higher than it is on the engine in the truck ('76). When I found out that the 727 in the truck was from 1965, I can only guess it uses a spacer to fit the larger crank pocket. The 1965 engine was purchased locally from craigslist and could have come out of any '65 Chrysler product. I don't know how many variations they might have had for stater motor locations.

The starter will be in the same location as it is now. The starter location is determined by the transmission. The only issue you will have is the fitment of the crank spacer/adapter to the crank pocket. It is even possible whoever put the late engine in the van, used the crank spacer/adapter for the small crank pocket (not correct but possibly done). You are going to have to take the engine out, and see what is in there for a spacer/adapter.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225