93 is a one piece rear main seal, and 76 is a two piece rear main seal. Rear crank shaft flange is different. You will need a flex plate, or fly wheel from the newer motor. Depending on if your truck is stick, or automatic.
In order to swith to carb you will need a carb intake to fit the fuel injected heads. Several aftermarket companies make them, such as Eldelbrock etc.
Dip stick tube in on the right hand side instead of the left like the two piece rear main motors, this should pose a problem, just puting it out there. The oil pans are not interchangeable.