You're venturing into uncharted waters with the hopes of using the front suspension / rear ends from either of those 2 donar cars. Neither of those are bolt-in parts, and I believe that they are (at least the '87 Mustang is) front steer. Your '66 is rear steer. The rears are not bolt-in swaps by any means. I'm not saying it can't be done...What type of fab skills do you have? I'd say find a Granada donar, or find parts from your specific year car.
I need some info on your current motor to be able to direct you in the right direction when putting the T-5 behind the I6. What is the casting number on the block (just under the exhaust flange), and tell me if the top cover of your current 3spd tranny has 4 bolts or 9. Also give me the casting number on the intake log of the head so we can see if they just replaced the head on the motor. That's a good and easy swap for better breathing on the earlier I6's.
For changed the 6cyl block bellhousing pattern in '66, then again in '81, right before they discontinued the motors (go figure?), so I need to know the specific casting number of the block to give you advice on the T-5 swap.
The T-5 is a great upgrade to the I6, but you will shread that 4cyl tranny behind the 302.
Al
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