Estimate horsepower from a 302?
I think the estimate of 250 hp is close..maybe a bit on the high side. Didn't say what kind of heads you're running, but the poster that mentioned the heads being a bottleneck is right on. The stock Ford heads are very restrictive. Better flowing heads are a "must have" for the Mustang. The Edelbrock RPM intake has a usable powerband of 1500-6500 if I'm not mistaken, is this matched with other parts on the car?
The weight for a 1984 Mustang hatch is about 3000 lbs. Depends on the variant.