well a buddy of mine delivered to my garage door a 302 out of a late 70s cougar, best of all it was free, my question is does anyone know if there is differences in this and a 302 i would find in a earlier stang, i want to put it in my 66 stang, also what will i need to do to make it compatible with the car that had a 289 in it, any input would be great thanks

 

I would say no because a 302 and 289 are the same block.

 

Hi sorry

 

It will slide right in. If it is an automatic, you should be okay with the balance specs, since the 302 is a pre-1980 model engine. In 1981, the balance factor was upped from 28 oz. to 50 oz.
(302 only, the 351 stayed at 28 oz.)

 

o the good news just keeps comin, i was pretty sure they were the same but not positive, the guy told me he was pretty sure it was a mid to late 70s cougar but it might have been early 80s, is there any way for me to check, i love free stuff!!

 

The 1968-1979 302s (and all 289s/351Ws) used a 28 oz imbalance. The 1981-up 302s use a 50 oz imbalance. What this means is you cannot use a flywheel, flexplate, or harmonic balancer from an old 302/289. Swapping the balancer and flexplate/flywheel WILL NOT WORK because the crankshaft is a different balance.
This is generally not a problem when using an automatic transmission, just be sure that your flexplate will fit in the bellhousing of your transmission. If it does not, you'll have to do some searching. This swap has become more and more popular, and aftermarket swap flexplates are available. Most machine shops can also balance your older flexplate/flywheel to the 50 oz imbalance. See if the intake is aluminum or not. If it is cast iron, you most likely have a pre-81 302. Also, count the teeth on the flywheel. If it is 157, then it is a 28 oz imbalance.