[76CobraIIjunkie]

I am almost done with my 351W engine build-up, I ran into a problem. The car had a 302 in it and a 4-speed transmission. The new clutch and flywheel i bought for the 351 will not fit into the bellhousing od the 4-speed. Does anyone know what clutch and flywheel I need to get to fit the 351w and the original 4-speed?

[5SpeedGT]

Use the one off of the 302. They are the same 28.8oz balance. The 5.0 didn't swith to 50.0oz until '82. You may be limited in clutch choices though.

The Mustang II used a really small and rare 143 tooth flywheel or flexplate. Everything else is either 157 or 164 tooth.

You're other choice's are to either swap in an older toploader, or a later model T5 5 speed. If the mustang II's used the SROD 4 speed, you can also score a bell housing from any '79-'83 5.0 Mustang which is also available aftermarket, as it is the same bell used for Tremec TKO swaps.

I went through this with my old '79 fox that had a 302/C4 from a II swaped in before I bought it. I needed a new flywheel, and couldn't figure out why the heck the one listed for a '79 wouldn't work.

[76CobraIIjunkie]

Ok sorry i didn't explain everything, the car when i bought it had a 289 in it and the same 4-speed. I sold the car when the engine blew to my brother and he put an 1985 302 in it with the 289 flywheel and clutch. He trashed the 302 with the vibrations of the mis-balanced flywheel. So all I have to work with is the 289 flywheel which is really small and the 351 flywheel that is way to big. So my question now is if I buy a flywheel for a 302 it will fit the 4-speed bellhousing?

[5SpeedGT]

I'm willing to bet that the flywheel from the 289 is the original one from the II.

Count the teeth on the flywheel and post it up, then we'll know what u need.

[76CobraIIjunkie]

The original one from the 289 is 148 tooth and is 12 and 1/8 inches od minus the ring gear. I can't seem to find any flywheels like this.

[5SpeedGT]

Yep, that's the original one from the II. Try a local parts store, and ask for one for you're year Mustang. I know they were still avilable a few years ago. If that doesn't work, any competent machine shop should be able to re-surface your old one if it's not damaged.

[76CobraIIjunkie]

ok, problem is that the 148 tooth flywheel is 28oz imbalance and I need for the 351w a 50oz imbalance.

[5SpeedGT]

Nope. 5.0L (302)'s from 1982 and newer are 50oz. All 351W's and 221-302(5.0)'s from 1962-1981 are 28oz.

[previouscobra2]

I put a 351w in mine and used all the old parts,never had a problem except starters.....but 351 was doggie as hell..(from van) lucky if it was 200 hp.Wonder if anyone made a mini-high torque starter for these?.....

[5SpeedGT]

289-302's and 351C/W's use the same starters. Any mini advertised for a 302/5.0 will work.