I have several choices I know and I probably have one in my yard but looking to up grade the flat head so I can add A/C I even thought about a 225 slant but what have y'all done to yours ? and what am I getting into i can do my own fab but just wondering what problems I know steering box and trans even thought about a jeep 4.0 I have one al though it a computer one 2000

Need to take measurements of the engine compartment and see what would be a good fit. A V6 might be a better choice than a straight 6. V8 if you have room.