Fast is relative, Hemi vs. Hemi

33IMP said

426 hemi hp was rated at 5000 rpm. Even if you give it power to six grand, enough to overcome drag, and a stick, so no converter slip, and stock 3.23 gears, and taller than stock tires, you get.......148mph
If you have a hemi Daytona, with 3.55s, a 727, and 500rpm PAST power peak?.......
114mph.
200? Ha ha ha.

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3.55 is roughly 10% lower (higher numerically), so I would think 3.55's would drop theoretical top speed about 10% from 3.23's. I.e., low 130's with 3.55. Am I miscalculating?

BTW, I have estimated the actual top speed of Dad's hemi (now mine) at just over 140 with 3.23 gears. How close that is, don't know. There are formulas, but it's hard to accurately figure torque convertor slip and tire growth, and just a small percentage difference can easily be worth several mph. Anyway, it has 4.10 gears now, so much lower top speed. I did once see 6100 rpm in my 65 340 Barracuda, 4-speed, 3.23 gears while drafting a 308 Ferrari. Again, long time ago. Have slowed down a bit in my old age.