I have a 428 (verified) that i am putting in my 1966 F100 to replace the current 352. I understand that i have to use a different flywheel due to the difference in the way the engines are balanced. The engine is all original (came out of a 1966 Galaxie) and in very good shape. My question is what is the size of the bolt for the crank pulley/harmonic balancer? I don't seem to own a socket that fits.

 

15/16th if i remember correctly.....why are you pulling the harmonic balancer? have you found the appropriate flywheel for it yet? and since no one else has said it here Welcome to FTE

 

15/16th should be

 

Will you be going with a standard or auto trans??

 

Going to keep the 4spd. Thanks for the info. Will have to get me a 15/16ths socket.