jangelo

Just purchased a 77 (L82 4 speed 13k miles) and haven't had a chance to pull the gas tank yet and I'm not sure if there will be a tank sticker left. Anyone with any help on determining which 4 speed transmission it has (M21 close ratio or M20 wide ratio).
It is a matching number transmission.The code on transmission is WA 772. I have seen in resto-guides where is says the 2 is for the close ratio but I have also seen where some say it represents the production shift. Based on other research I'm begining to think it represents the shift as I've seen L-48's and and M-20's with the last digit with a 2 which obviously wouldn't have a close ratio 4speed.
It's sat since 89 so I won't be able to do the shift test any time soon as recomended elsewhere on here.
Any help with this is much appreciated.
Thanks

BKarol

2 = production shift

http://www.pontiacpower.org/BW.htm

jangelo

Thanks, this helps reassure it represents the shift, but it doesn't help me identify which one it is.

LeMans Pete

Jangelo,

Other alternatives I have heard before to confirm a BW ST-10 close ratio is an ink stamp of HW. Maybe yours is clean enough to find the stamp, but any solvent you use to clean it will be sure to wash that stamp away.

A second method I have heard is that the input shaft on a close ratio has 2 ring grooves, compared to a single ring groove on the wide ratio. Obviously you'll have to separate the transmission from the engine - not worth it to confirm an M21.

I have also heard that the final "2" is for close ratio. NCRS leans to this idea (I say lean because it is not definitive).

I do have a 1975 L-82 with a close ratio. I have confirmed it from the tank sticker and I also have the final "2" on my date code. I also have a two ring groove input shaft.



Very tough to read, especially in a picture, but I can read L82 with M21 directly below it.


Two ring groove input shaft.


And finally, matching VIN with CHC (L-82, 4-speed) suffix.