DYNO RESULTSFORD BOSS 302 vs CHEVY DZ302. WHO DID IT BEST? Check out this comparison between two hot, 1969 302 (5.0L Trans Am) Muscle Car small blocks. How does the Chevy DZ 302, with higher compression and wilder cam timing, compare to the massive head flow of the Boss/Cleveland 302? Both were factory rated at 290 hp, but did either one really make (only) 290 hp? Did the huge head ports in the Boss 302 hurt lowspeed torque? Did the stock DZ really rev to 8,000 rpm? Find all the answers to the myths about your favorite 5.0L Trans Am small blocks right here! Full dyno results.