What rpm does 3:91 gears give at the end of the 1/4 mile

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Assume 10 percent converter slippage if you have a 3500 {ball Park}
My 70 Dart 3.91 gears, 24.5 tires, 1 to 1 trans ratio, 500 hp, 3500 converter with10 slippage should cross the line
6200-6300 which is as far as im willing to turn my 360 mag with stock heads, crank, block, rods , pistons