" Compare Two Transmissions Enter the tire diameter, RPM, and rear gear ratio Tire Diameter RPM Rear Gear Ford Toploader (wide)Ford Toploader (close)Tremec TKX (close .68)Tremec TKX (close .81)Tremec TKX (wide .72)Tremec T45 Ford Toploader (wide)Ford Toploader (close)Tremec TKX (close .68)Tremec TKX (close .81)Tremec TKX (wide .72)Tremec T45 Gear Ratio Speed Ratio Speed