Just something interesting i thought i'd post. I have a 96 cobra and the guy i bought it from put an 03 terminator t-56 and irs in it with the stock 3.55 gearing, wich made my speedo about 10 off. I rebuilt the rearend and put 4.10s in it, now my speedo is within a 1 mph lol, kinda glad i didn't buy a speedcal when i bought my gears :laughing4: