5 speed swap

tante azares

New Member
Apr 13, 2008
i want to convert my '70 mustang sportsroof with a 351W and 4speed top loader to a 5-speed. ive read the info on MODERN DRIVELINE and STANGNET. my question is does anyone know the weight differences of the toploader, T5, 3550,TKO. also what are the torque ratings of these transmissions. i have raced my mustang at the dragstrip ( best time is a [email protected]) but have been inconsistent with the original toploader with the original Hurst shifter. the mph indicates (quartrjr) approx 425rwhp. what vehicles were availabe with the tremec 3550 and TKO? i have 4.11 gears in the 9 inch rear and would like to have an overdrive to better cruise on the highway.


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All of your technical data questions are available, some searching should ferret them out.

I can tell you that, based on the info you have provided, you do not want a T-5. A 3550 or TKO is in your future.
Why not buy a gear vendor? There are some that are rated to ridiculous power levels that will allow you to have the overdrive that you need. It will cost about the same as a new transmission and misc parts but without the hassle of swapping.