I am running a 12 bolt with 4 series spool. I am looking for a 3.73 Pro gear, as I have destroyed my 3.73 Richmond street gear on the first launch. I have been searching the web and have found nothing... Can anyone lead me in the right dirrection on this???
Every set of pro gears I have found start at 4.11, I would actually rather be a 3.55, but have settled on the 3.73 because of the 4 series spool.

Thanks,
DonB

 

I'm 99% sure the 4-series spool is what isn't allowing the lower ratio, I believe a 4-series carrier will only allow a 4.XX+ gear due to the offset of the gear mounting flange.

I don't even believe you can get any 3.XXX ratio gears for use in a 4-series carier.

 

Dave: you probably know this, but if the car is used on the street, the pro gears are going to wear out pretty quick. Sorry, I don't have an answer to your question other than to call Moser or Randy's.

Rich

 

This is strictly a drag car, so no street use at all. I know about the 3 vs 4 series, that is why I have the 3.73's (no 3 series spools or 4 series 3.55's).
I am already running a 30" tall tire and need the lower gear ratio to keep it around 8400rpm through the traps.

I will be making some calls in the morning as none of the gear manufacturers have anything listed in that ratio.

Thanks,
DonB

 

First off, you can get a 3.73 gear for a 4 series carrier.... it is a special "thin" gear set. I've used these before.

The unfortunate thing is if looking for a pro gear, all of the ones I have seen are 4.11 & up.

Now, unless you have an 8 seccond car, you should be fine with a standard gear set if it is properly setup. Set the gears up with minimal backlash & use a support cover. I broke a lot of Richmond sets & no longer use them. I've had great luck with Motive. Don't use pro gears unless you plan frequent replacement.

 

Lonnie,
I have the 3.73 4 series setup now, but broke them on the first pass. They were set up right and had the support cover also. I am running a high HP combo that should run in the lower half of the 8 second zone.
Thanks for the help,
Don Barnett

 

Guess that supercharger is working pretty well....

You may want to try a different brand. Your luck may be better.