Flywheel differences

[Gud T.B. Blown]

is there a difference in the manual trans flywheels from a '70 351C and a '73 351C in terms of internal balance? i have some vibration and i'm trying to narrow down the source.

 

[shotsy]

I think the flywheel weight depends on how the crank is ballanced. According to the ford preformance parts web site the 70-74 351C's were all 28 OZ ballanced cranks so the flywheel shoud match right. The 50 oz wasnt used until the early 80's.

 

[Gud T.B. Blown]

thanks, that's one item off of the list.

 

[shotsy]

Motor/tranny mounts in good shape? Is the funny vibe through the whole rpm range or just at idle?

 

[Gud T.B. Blown]

it's on deceleration only @ 45mph, i don't remember the rpm. the vibration is there whether i am in gear or not. the tranny mount is new, the motor mounts are probably from the engine swap at least 10 years ago, maybe even the original mounts.

 

[shotsy]

Could be bearings in the front coming loose? I'd doubt it's drivetrain if it's only happening on deceleration and out of gear. What kind of shape are the front rotors in. Brakes applied or not when it's happening?

 

[Gud T.B. Blown]

no, it's definitely driveline vibration. i feel it in the shifter handle and that happens both in gear and out. the brakes are not applied. thanks for the help.