[bluegoose66]

I am looking for a 1966 GTO 4 speed driveshaft. I have a bunch but need a measurement. It has a 1971 442 Muncie with the th400 size output shaft. I need a yoke also.

['ol Pinion head]

The original driveshaft for a '66 GTO or 2 door LeMans with original small output Muncie 4spd /OR/ with SuperTurbine 300 automatic will be 60.00" long, center to center on the u-joints. When the Turbo400 was introduced for '67 model GTO's, it required a 5/8" shorter driveshaft (59 3/8") and the shaft used the medium length Turbo 400 yoke ('67-aprox '75 usage).

When the big output shaft Muncie 4 speed was first used in Pontiac A-body's ('71 models) their driveshaft was 5/8" shorter than same model previous '68-70 Muncie 4 spd applications. This length was same as same '71-72 models with Turbo 400 (55 3/8" center to center).

Forgive me for long round about answer... your '66 will take a 59 3/8" (center to center) driveshaft, 3R ujoints, & will need a medium length Turbo 400 yoke which accepts a 3R ujoint.

[bluegoose66]

Thank you for the help. I saw the measurements before but no one could tell me where to measure from.

[Frank R]

I have a driveshaft from a 67 with a Turbo 400 and big yoke. It measures 59 3/8" center to center. I think you need a 60" driveshaft like the one in my 67 with a 4 speed.