i have a sct tuner with a 91 octane 3.73 gears and 17"in rims TUNE. should i mess with the spark, WOT air/fuel ratio,? or anything like that?? i check my axel ratio and it said stock? but my speedometer is fine but should i put it on 3.73 even though its on the 3.73 tune? what all can i do inside tha tuner to get all the performance i can get out of it?