I'm swapping in a 400 in palce of my tired 351m. Will the flywheel off the 351 work on the 400? Any balance issues that anyone knows of? I know the dampners are different but wasn't sure about the flywheel.
Thanks for any info.
Brian

 

yoda777,

The 351M flywheel will work on the 400, as they have the same balance. Ford used the same castings for both 351M and 400 flywheels.

However, you cannot use the 400 12" clutch on the 351M flywheel (11" clutch) unless you have the outer holes on the 351M flywheel tapped for the pressure plate bolts.

If you're rebuilding the engine, I recommend having the entire rotating assembly balanced for optimum performance and longevity.

BubbaF250

1980 F250 4x4 Custom, 351M/NP435/NP208/D44HD-TTB/D60-FF/3.55s 6750 GVW, Rust & White.