I have a manual flywheel for a 1988 460. Will it work on a 84 F250 I want to change to manual

 

Most Ford engines are externally balance meaning a match between harmonic balancer,crank and flywheel.I would check first is the balancer the same between the 84/88(most likely) and then check for the flywheel just look up the parts online.I ran a 429 back in the 80's and cannot remember if she was internal or external?I looked it external balance

 

Yes it will fit and the balance is right.
Are you swapping a ZF5?

Just be sure the flywheel is drilled correctly for your pressure plate.

All 429's that would fit a pickup were internal balance from the '70's.

Not sure when 370 and 429 medium. truck/stationary engines changed, but the big snout won't fit behind the radiator of a pickup

 

79 and newer 460s are internally balanced

 

... a running change *during* the 1979 model year build.
Numberdummy will corroberate.


So '79 could be internal or external.
The telling factor is a D9TE block and the hatchet weight behind the harmonic damper.