373 gears

**real_jeff** · 04-23-2007, 01:42 PM

I'm going to have some 373's put in and I was wondering about the speedo gear I need to put in?

**J-rod** · 04-23-2007, 01:43 PM

white 23 tooth.

**Pure Stock** · 04-23-2007, 01:48 PM

Originally Posted by real_jeff

I'm going to have some 373's put in and I was wondering about the speedo gear I need to put in?

It really depends. Tire height and speedometer *drive* gear will dictate *driven* gear needed. What size tire (height) and what year is the trans?

**Stangzrule** · 04-23-2007, 02:24 PM

Got a brand new white 23 tooth if that's what you need.

**Cam99** · 04-23-2007, 02:25 PM

Originally Posted by Pure Stock

It really depends. Tire height and speedometer *drive* gear will dictate *driven* gear needed. What size tire (height) and what year is the trans?

I'm going to piggy back on this thread. 93 t-5 and 26" diameter tires. What is the diameter of stock size wheels on 16" pony wheels . 26" also?

**real_jeff** · 04-23-2007, 03:57 PM

P225 16 or 25" Diameter. '95 GT 5 Speed.

**RUSH2112** · 04-23-2007, 05:51 PM

That's what I got with my 3.73 gears, white 23 tooth
Stock wheels also. It's about 3-5 mph off

**Pure Stock** · 04-23-2007, 06:12 PM

Originally Posted by Cam99

I'm going to piggy back on this thread. 93 t-5 and 26" diameter tires. What is the diameter of stock size wheels on 16" pony wheels . 26" also?

The 225/55/16 tire diameter will vary somewhat depending on manufacturer. It's safe to say it will be close to 26" though.

So we take the 26" tire height and multiply it by pi (3.1416) and arrive at circumference, that being 81.68". Then divide 63,360 (inches in one mile) by the circumference(81.68") to arrive at tire revolutions per mile. That value being 775.7 tire revolutions per mile.

Then use this formula to calculate speedometer *driven* gear needed.

Driven gear teeth= drive gear teeth x axle ratio x tire rev. per mile DIVIDED by 1000

8 x 3.73 x 775.7 DIVIDED by 1000=23.14

Looks like a 23 tooth speedometer gear would be the closest match.

**Pure Stock** · 04-23-2007, 06:34 PM

Originally Posted by real_jeff

P225 16 or 25" Diameter. '95 GT 5 Speed.

25" tire height = 78.54" circumference. 806.72 tire revolutions per mile. Now just plug those values into the formula:

8 x 3.73 x 806.72=24072.525 DIVIDED by 1000=24.072

23 tooth driven gear looks like the closest match in your application.

**Pure Stock** · 04-23-2007, 07:07 PM

As a side note: The 23 tooth driven gear is produced by a manufacturer other than FRPP. Due to the pitch of the teeth on that particular speedo gear abnormal/premature wear can occur because of the pitch differences.