I've had my 46 pickup for many years and what I did was keep the stock bellhousing with it's beefy side mounts. To that I can bolt on any 216, 235 or 261. Behind that bellhousing with an adaptor I can run any modern stick shift trans. You can go any route you want but for me this has worked out great. Now running a T-5, engine is 261, plenty of power for these light weight trucks.
Best of luck.
