Information on the 273
I used a 4.56 rear end ratio in my 273 bracket racer, launched and power-shifted the four-speed at 6,000 rpm and the trap speed on a good run was 6,400 rpm and still climbing. Looking back on it now, the way it was still roaring and accelerating at the quarter-mile mark, I believe the vehicle would have benefited more from a 4.88 or even a 5.12 rear end ratio. As it was, we had best of 108 mph at 12.72 elapsed time with the four-barrel 600 CFM Holley double pumper.
I used a 4.56 rear end ratio in my 273 bracket racer, launched and power-shifted the four-speed at 6,000 rpm and the trap speed on a good run was 6,400 rpm and still climbing. Looking back on it now, the way it was still roaring and accelerating at the quarter-mile mark, I believe the vehicle would have benefited more from a 4.88 or even a 5.12 rear end ratio. As it was, we had best of 108 mph at 12.72 elapsed time with the four-barrel 600 CFM Holley double pumper.