hey guys ... after thinking on it for a while I went ahead and got a new motor, Its a 1981 302 bored 0.60 over fresh out of the machine shop. My question is and I have had a problem with this in the past will the flex plate work that is on it with my trans ?? the car has a 1979 block in it now and I think thats a 28oz front and rear , Is the 81 the same ?? or is it the 50oz and if it is the 50oz will it work with my c4 and starter?? My 79 block has a new harmonic on the front and I would like to just swap my flexplate and harmonic off the 79 onto the 81 is this possible?
Should be the same, double check with your machine shop to make sure before putting everything together. I've learned the hard way before and its not a good feeling knowing you have to pull it apart and start over again.
81's going to be smack in the middle of when Ford went to the 50 oz cranks. Compare the size of the counterweights of your 79 and 81. If the 81 has noticably smaller counterweights, it's a 50 oz unit.
Yep looks like I was wrong, not good cause I just went through this. Looks like I get to do some double checking on my engine....... great From the FRPP site FAQ http://www.fordracingparts.com/faq/faq.asp Q. What is the crankshaft balance factor of my 302 or 351W/C engine? A. 1968-80 302 engines were built with a 28-ounce imbalance factor. 1981-2001 302 engines were built with a 50-ounce imbalance factor. 1969-97 351W engines were built with a 28-ounce imbalance factor. 1970-74 351C engines were built with a 28-ounce imbalance factor. Note: Severe engine damage will result if you use the wrong flywheel or damper on your engine
well its not a big deal to me considering I have both now that I know the 81 has a 50oz. My harmonic on my 79 is a summit racing one that can be a 28oz or a 50oz ... so now the only question is will the flexplate on my 81 work with my C4 and starter ? do I just size them up and see if they are the same size?
But your wife/girlfriend (whichever or both) will love the vibes if she's sitting in you lap while you drive.
if you go to autozone.com and look for an 81 Thunderbird < what my new 302 came out of > It says its a 28oz....that would mean its the same as my 79 ... This is confusing I read one place its a 50oz and they switched in 81 , then I read its a 28oz and they changed in 82... OH and BADDAD I'm sure she would love it but that is one expensive vibrator !!!! lol
Like I said before, Ford made the switch sometime in the 81 model year, even they don't know exactly when. Best thing to do is compare the counterweight size between the 79 and 81 motor if in doubt. The 50 oz weights are much smaller than a 28 oz cranks weights.
But then that means I have to take her for a ride in my car! She smarter than that to ride in any of my death traps! LOL Yeah I had both flywheels sitting on the shelf to, and while we were putting it together my father inlaw said 28 ounce right? (ME) I said yep 50 oz started in 86. (HIM)He said you sure about that? (ME)Yep I'm sure! Now I'm glad he is in Arkansas until next month.................... Got a chance to swap it before he finds out, or I WILL NEVER here the end of it!!!!! LOL:bananaman
