jackskid

3:73

OneFine89Mustang

3.73

ecal533

I have an 03 cobra, 6 speed, kenne bell, CAI, BAP...it's was dyno'd at 537 to the wheels. I upgraded my 8.8 IRS to an Cast Iron unit with 3:73's. I did it for more strength and because my old unit was whining and after 3 attempts to set it up with new gears / bearingsthey said it was just plain tweaked. My problem now is that even the cast iron unit has a small amount of noise on accell and decell so I am taking it to a more reputable place. I considered going 4:10's this time because of the six speed. I think with 3:73 I could run 65-70 at about 2000 rpms. The thing is that modular motors seem to start making usable hp at 2500 and up.

Anyone running 4:10's in a 6 speed cobra? what are the rpms at 65-70?