Ok I'm not goin to waste money since I have them on my 95 4.6 bird its the steeda non piggy back style just wondering if its worth the work to switch them out......... on my bird it made a hell of a difference at the track at best of a 3tenths and an average of 2tenths better since switching them out......cuz I know that thes marks suffer low end torque........... so anything to help spin faster