Idea: I was reading that back in 1983 Herb Adams sold a 170mph speedometer recalibration kit. Since the 82-84s have speedometer driven by cable, the kit consisted of a 50% underdrive gearbox (it acts as an mechanical interface between the end of the speedo cable and the gauge itself) thus the mph on the gauge indicated half the actual speed. So if the speedometer was reading 40mph you were really doing 80 mph.
Now fast forward to 2001. Make a WFG using the 85 mph template and just change the numbers to double what they are. Instant working accurate 170mph guage for early thirdgens with very very little work and without having to do the conversion to electric speedos.
Question: Does anyone know who carries speedometer recalibration kits, such as the one listed above?

 

Keep in mind that your speedometer cable cable re-callibration thingie MIGHT just be a little illegal. Since you are taking your speed & cutting it in half, you will also cut your miles in half. So with a your new template you will read the correct speed, but for every 2 miles you go your Odometer will read 1 mile. (great for keeping your miles down.

I think the name of the part your looking for is a "Reducer"

John

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G O D BLESS AMERICA

http://www.3rdgenformula.com
87 Formula 5.1 TPI Auto Modified (Yellow/Black)

87 Formula TPI (5 Speed) Yellow/Gray STOCK

14.8sec 1967 Buick Riviera
1990 Buick Riviera (driver)
83 Camaro
83 T/A

 

Hmmm.....that never crossed my mind. Thanks for the heads up, but I am still going to try it anyway. I never plan on selling it, and in another 7 years when I am eligible for "classic" registration status (25 years)in NY, I will actually be able to drive it 6000 miles a year instead of the 3000 mile cap. Yip-eee.

For anyone else interested in the idea, I found a place that sells the part required for this "conversion". This is the email I received from United Speedometer Service in California usimail@earthlink.net :
You can use the NPN-800-series - 7/8" offset type ratio adapter on your '83 Trans Am. The cost would be $66.84 + shipping.

I am still going to "shop around".

 

Herb adams still sells that I think, I believe i asked him about it when I called up VSE(Very Special Equipment) about my Fire-Am Decals. I'll get you the number if you want.

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1983 Pontiac Firebird

Chevy 2.8L 60° V6

Mods:
?K&N XStream Air Filter Lid
?Edelbrock Performer 2BBL. Intake
?Edelbrock 2.8L Chrome Vavle Covers(Comming Soon)
?87 Formula "Power Bugle" Hood
?110watt Pilot Driving Lights
?Grant Signature Series GT Steering Wheel
?Bosch Platinum +4
?8mm Bosch SparkPlug Wires
?KOSS 200watt CD Head Unit
?Pioneer 2-Way 200watt 6x9's
?Hi-Flo CatCo CAT
?Flowmaster 80 Series Muffler
?83 Trans Am 15x7 Turbo Fin Wheels With WS6 Centercaps
?B.F.Goodrich Radial T/A 225/60-15
?Chevy 2.8L Heddman Headers (Going on soon)

Aol instant messenger: FIREAM

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