I have decided to replace the factory 3.27 track lock with The FMS 3.73 unit. The factory one has a howling problem related to a pinion seal failure that was not properly repaired by ford. I have recently added the the A.R.T exhaust system and have notice a loss of torque with the new system. I did gain mph and lower my et but a lot more power comes in in the upper rpm now. I want to lower my et and increase my mph by 3-4/10 and 3-4 mph. I am currently running 14.5 95mph at 3500 foot above sea leavel. The stangs were running 15.1 and the gp sc were runing 15.5-15.6. I want to break into the 13s and mabey low 13 when cooler weather gets here. The temp was 95 degrees. Do you guys think that I will have driveabilty problems with 3.73 gears? Is it possiable to snap the axils? Do you think that low 13 are possiable with this combo and cooler weather?