Yes, I completely agree with you on installation with an open drive-shaft transmission.
". . . original 216 engine back in my '53 1/2 ton truck . . . the transmission was left in place . . . "
And, I agree with you with an enclosed drive-shaft, if you need to open up the u-joint/cover to service/replace the u-joint and/or the gaskets/seals for the u-joint housing.
