The 302 engine was conservtively rated at 290 bhp gross, though it was estimated that its actual power was nearer 400. hardly surprising when one considers the engine used what was know as "Cleveland" heaads, possessing huge intake and exhaust valves, aluminum high rise manifold, Holley 4 bbl carburetor, forged crankshaft, and special pistons. Actually the Cleveland heads were scheduled for 1970 production but their breathing properties were superior to equivalent 1969 heads and convinced Ford to use them on the mid-1969 Boss.
Considering it's size compared to the 428 CJ, the 302 was no chicken. It could race to 60 in 6.9 seconds and hit the quarter in 14.85 seconds at 96.15 mph. Not as quick as a Camaro Z-28 with a similar-size engine, it took exactly the same time to reach the quarter, but it's trap speed was just over 101 mph. The proof, however, is in the driving, and Camaro proved that, with an impressive Trans-Am season capturing the crown for the second year running. Nonetheless, Mustang's Boss 302 won a couple of the 12 races in convincing style, serving warning to Chevrolet that this was only the beginning.
Here is a picture of a 1970 Boss 302. The only differences between the 1969 and 1970 are the headlights, which the 70 has two nd the 69 has four, and the side turn signal marker, which in the 69 is horizontal instead of vertical.