ChesterKaup

I am thinking of putting a supercharger on a 2004 V8 Automatic mustang. Will this transmission hold up to the extra power?

BAMFingOh10

While I cannot speak on the limits of the 5R55S, The Tremec TR-3650, which a 7.5 cannot handle hence why manual sixers get T-5s, comes stock in the GT with an engine pumping 300 horses. Automatics get Ford's one size fits all automatic 5R55S 5-speed transmission. These trannies will probably become obsolete as the 2014 Ecoboost will probably have a 6 speed auto/manual, and I suspect the 2011 may be getting 6 speeds across the board, since it seems 8.8s across the board would be too expensive, and they've got to control the extra ponies better.