I have a ford 9 with 4:11 gears and I'm thinking about changing them to a 3:89 ratio. The trans is a ST-10 with 288 first gear.The rear tires are 31" tall M/T sportsmans, I also have a set of 30' tall M/T et streets. Besides less rpm in fourth gear what will happen to 1/4 mile times? How would it affect 60' times?

Thanks for the help!

Rick,

I think it all depends on how your car is running at the end of the run. If the car is out of rpm at the end of the track, then I would say yes the gear change will help. As far as to how much it would help I think you will need to post your car's specs and time slips for our racing gurus !!!


Bill

Sorry no time slips yet. I would have gotten some yesterday but I pulled the center section the other night because the rear was making noise when cruising in 4th gear and at low rpms you could hear the gears hitting. The rear didn't make noise when it was first put in 5 years ago. The backlash was way off and I also found out the carrier bearings are going bad. The races were grey and 1 bearing showed signs of flaking. You can feel the difference in the gear teeth where they mesh and don't touch at all.