Quote Originally Posted by 460motorvator View Post
Can you help,as i am going to buy a 521ci eagle conversion kit but,the one i am being supplied is externally balanced,my engine is 1976 460ci internally balanced,being told that all i need to get is a externally balanced spacer behind the harmonic balancer?Can i still use the same balancer,ie, not neutral,internally balanced? Are there any differences with the later crank,ie,rear seal locations?
What is the differnce between 1968-1987,460's,to later engines?
The external balnace rotating assembly will fit the 1976 internal balance engine block (D1VE). All 429-460 balancers are neutral balanced, however the flex plate and crankshaft spacer (between the balancer and timing cover) are different between itnernal and external balance engines....so you need an external balance flex plate and an external balance crankshaft spacer, also known as a hatchet weight.

Paul