Does someone have a list of speedo drive and driven gear selection? Color codes, too, maybe? I have the formula: Drive Gear x Gear Ratio / Tire Diameter x 20.2 = Driven Gear. 10 x 3.90/27 x 20.2 = 29 (for a 255/60) I'm looking for 10/29, 11/32, or 12/35 tooth combo for the 255/60 (27") or 10/28, 11/31, 12/34 combo for 275/60-15 (28"). How tough is it to swap these? Which one is in the speedo housing (driven, right?)? If the drive gear is known it should be fairly easy to swap the driven? I want to get the speedo accurate without spending big bucks on a programmable unit and mess with the pulse generator, etc. A simple mechanical 160mph unit is all I'm after. Thanks.
Gary, TCI lists all the gears with part #'s here. Scroll down to the 200R4 gears, a 10 drive gear is green, a 29 tooth driven gear is also green. Click on the yellow tab for part #'s. http://www.tciauto.com/tech_info/speedo_gears.htm
Are you thinking of running a Buick in the Silver State? I'd love to hear about that car!!!!!! I've thought about building a road car for something like that. That would sure have to be a purpose-built car to compete in one of those races. But I know there are some guys out there that are running a '68 Charger that supposed to be able to do 190 MPH!!
Thanks Larry. I called in my gear numbers to Art Carr for the refresh. John, hmmm... Phil, I can't afford to build it to run in the upper classes but it's quite capable of 150+mph if the aerodynamics (or lack of) will allow. I have the GW upper/lower, big swaybar, Hotchkis adj. rear upper, OD, etc. As you know I have the Monte SS steering box that's leaking so that will have to be fixed. Putting new body bushings in now to go with all the good suspension stuff. But, I'd have to add a roll cage, Z-rated tires requiring 17" wheels ($2k right there), fire suit, etc., etc. to run in the upper classes. Rear discs would probably be an excellent idea, too. All go and no whoa at those speeds is just plain NUTS. However, I can run in either the 85 or 95mph class or even the 115mph (average) which have a top (tech) speed of 124mph. They run a pilot car out front - if you get caught on radar at 124+ or pass the pilot, you're DQ'd. So I guess a guy could run 120 for the whole race without breaking the rules but there'd be no chance of a win against the clock. For my money that might be the way to do it for a one-time thing. The race locally is 45 miles x 2 so would only be about an hour of seat time. Also, it's about $400-600 to run with a navigator, even in the slower classes so is pretty spendy for a bit of fun. I do think I'd like it better than the 1320' though (not that I don't like that). I think Global West has a 200mph Chevelle, too. Lots of folks can't believe an a-body could run those speeds (never known for handling ability) but they don't understand the new suspension technology out there for these cars. I honestly don't know if I have the guts to push the car close to it's limits in the twisties, even with 15s. Check out the webpage for the race outside Elko. http://www.openroadracing.com/html/gamblers_run.html
