5.0L Conversion Flywheel Question

[EVB]

The Vehicle:

It's a 1972 EB that has a 1991 EFI 5.0L from a GT Mustang. A NV3550 from a 2001 Jeep and the conversion kit from Advance Adapters. It uses the original 72 3sp belhousing, modified with the adapter plate from AA. And also the 72 presure plate and starter.

My problem:

VIBRATION, not when driving but most noticible just sitting in neutral and you touch the gas and it revs up then down to idle. Shakes the whole truck.

Reason: (i think)

The 91 motor is supposed to have a 50 oz flywheel and the one from 72 is only 28.2 oz.

My question:

Back when the swap was getting done we had both the 91 mustang flywheel AND the 72. There was a fitment problem because the mustang was 157t and the 72 needs a 164t to make the starter work. BUT now I found out that the balance is off and I can't find a 164T in a 50oz !!! There has got to be a way to either make this flywheel balance to 50oz OR make the mustang flywheel work in the 72 belhousing.

Anyone got some advise. I know this is not the only EB out there with a 5.0L.

Thanks.

 

[brewchief]

i think you will have to change the bell houseing to a 157t model maybe a 3 or 4 speed car version? i have been told that they all bolt to the trans the same but i am not sure i used a c-4 with my 5.0