Customs SBF 302 Flywheel ID

Okay all.
I have a 63 Falcon and the 302 that is in it has the E0AE stamp, so an early 80's motor. I am swapping out my T5 for a TKX and I am about to mount the new McLeod flywheel with bolt on weights. I think I should be using the 50oz weight as opposed to the 28oz.
Here is a picture of the flywheel I pulled off last night. It looks like the 50oz, but the 3 holes drilled in the weight casting were making me second guess myself. To add a little more confusion, the rear main seal I pulled off was a National 3909 1-piece.
Any help would be greatly appreciated. Thanks!

 

That is an 81 flywheel. I think Ford went to 50 oz. in 82. Is the oil dipstick in the block?

 

dipstick is passenger side external

 

The truth is there are actually three different balance sets for the smallblock Ford, a 28 oz, a 50 oz, and a one-year only balance setup that was used on the engine my unwitting friend installed in his short-bed unibody pickup. When he replaced the harmonic balancer the engine developed a vibration, he then swapped to the other balance set and the vibration got worse, puzzled, he then went to the dealer where he found out the awful truth. Luckily a nationwide search found the last known correctly weighted harmonic balancer in the world. Gotta love FoMoCo.

 

Pretty crummy picture but here's a side by side comparison of the flywheels:

 

That is a 50oz wheel. If you find a one-piece rear main seal, it's the 50oz balance unless someone has been into the motor. Ford phased these in starting in '81, not all 302 motors had the 50oz balance until '82.

Your buddy probably had a 255, or possibly a 255 crank as a budget stroker for 320". Visually identical to the 302 and commonly mistaken as one, it had an oddball bore/stroke of 3.680 x 3.126 so did balance different. Ford built these in '80/81 in response to the second oil crisis, but was such a dog it was gone quickly.

Chevy did the same thing, theirs was the 262 and was also a dog.

 

thanks guys. going to bring the old and new flywheel and the pressure plate to the machine shop today and have them match whatever that old flywheel is. It looks to me like whoever built the engine balanced the flywheel with those 3 holes. better safe than sorry I guess. I would hate to get it all back together and have to tear it down again.....I'll post the findings once I have them

 

A bit of a correction: The 255 had the same 3.00" stroke as the 302, and the later 302 imbalance of 50 oz-in.
It did have a 3.68" bore.

 

I believe the '68-'80 302's were 28 oz and the '81-'92 were 50 oz.