Join Date: Nov 2000
Location: Blythewood, SC, 29016
The big block heater box replaces the small block box, so the holes for the heater core will be eliminated. You will need the correct (read original) motor mounts if you want headers to fit right. You will also need all accessory brackets (PS, alt, etc) and a radiator for a big block car. Your front springs will also be sagging from the additional weight, so they will need upgrading (great time to rebuild your front end). Also a good idea to rotate the wiper motor to clear the valve covers if the motor is mounted down. If you have power brakes, you must either use short valve covers or dent the covers to clear the booster.
Good luck, and I am sure more knolwedgeable people here will post as well.
57 Plymouth Savoy in my family since new, just cosmetically restored, 93 S-10 waiting on the 80 Dodge Lil' red Express clone truck to be built then one s_10 for sale, Angie's mechanic and designated Vette cusser.