Join Date: Feb 2010
Location: Virginia U.S.A.
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This is a good subject. In 1965 there were three 4 speeds to choose from.
M20 (wide ratio) used with all factory available axle ratios except 3.90. (code W).
M20 (wide ratio)
wide ratio used when 3.90 rear axle was special ordered (code 9).
M21 (close ratio) (code 8) could be ordered on the All Series Special Equipment Order Form (sales code 778) but was only available with GTO, Tri-Power, and 3.90 axle (you were not required to order the M21 to get the 3.90 axle).
What the original poster was reading is about the sales code 778. This is the M21 trans and it requires options 432 (HD radiator), 692 (metallic brake linings), 701 (safe-t-track), and the 3.90 ratio, with the tri-pwr GTO option.
You didn't have to order Sales Code 778 to get the rest of those options. If you checked off the 4 spd option on the regular Order Form and listed the 3.90 axle on the All Series Special Equipment Order Form, Pontiac selected and installed the code 9 trans (the only difference between it and the code W is the internal speedo gear and neither will have the groove ring because both were wide ratio). In this option you could choose not to have safe-t-track.
Last edited by Roger that; 02-11-2015 at 12:25 AM.