I had a '76 Cobra II with the 302. Yes, it was based off of the 289 but the stock 289 had much more horsepower than the '76 302. When I was done with mine, it had forged Boss 302 internals and forged TRW pistons. ( I was fresh out of automotive tech school and had nothing better to do) But in reality, you were driving a Pinto dolled up to make it look like a Mustang. The big compromise with this car was trying to get speed parts in a Pinto. I had the headers modified twice to get them to fit. The dual exhaust was a compromise because both mufflers had to sit on the passenger side because of the gas tank location. The engine oil pan sits really tight next to the engine and had no room for a windage tray. The C4 tranny uses a small diameter torque converter and bell housing that was used in the V8 Mustang II cars only. Also, I'm 6'5" and just driving the car was interesting.
The only redeeming value to that car was that it was a chick magnet. You can't believe how many gullible women wanted to get into the car just because Farrah Fawcett drove the same car on the "Charlie's Angels" TV set. You gotta remember this was 40+ years ago and I was an invincible teenager.