I have muncie M20 trans with a 2;52 first gear(3885010)-P7C01. I have a 12 bolt rear with 3.08 actually 3.07 gears. Can anyone tell me what plastic speedometer gear to use. thanx wnk.

Try using the blue one, 20 teeth. Thats what was in my muncie before I switched from 3.08 to 3.42.

What size wheel/tire?

My '72 Nova has 3.08's & 225/60-15 tires. The drive gear has 8 teeth, & the driven gear has 19. It reads just a little bit fast (<2mph) at 70mph. My '69 6-cyl. came from the factory with 3.08's & the same speedo gears, but I can't remember the exact tire size (they were 1 size smaller than standard '69 Camaro tires).

hey blue69,

What was the tooth count for the 3.42 set up ?
I changed the rear end last year from a 2.56 to a 3.42 but never got around to the speedo gear. It broke on the weekend and I plan to get a new one from GM. Thanks

macdon,
I went to a 21 tooth gear(red). I am running 245/60-15 BFG's. Seems to be pretty close to correct, at least close enough for me!

Blue 69
Thanks, I am running the same tire size so Red is the one I'll get tomorrow.

Macdon and dusted
You have mail.
Jim