OK, after looking at the trans and checking the casting numbers against the specs I've downloaded from various sites, what I have so far is this: Main case # 3925656, Extension housing # 3873886, and serial # 191516691, plus L198 cast into the main case, and GM6 on the extension housing. The numbers translate to a Camaro built between 1970-72. Did Chevy paint Camaro transmissions with the same blue-green color that Pontiac used for their engines in those same years, or did the same casting numbers apply to both Chevy and Pontiac models? Another minor mystery is the serial number location. It's on a machined pad on the upper right side of the main case, and according to what I've been able to find about Saginaws, it shouldn't be in that location for 70-72 model years. The # on the side cover is GM3920738 (I think; the last 2 digits are blurry and not very distinct). I also have a question about the grooves in the input shaft. Are they machined into the spline area or are they on the smooth section behind the splines? It looks like there is what could be a groove in the rear section of the splines, but no grooves on the smooth section. And I guess I'm wrong about trans not coming from a Camaro. I may have to recheck some of the research I've done, but I'm still curious about the anomalies with the paint color and serial # location. Anybody have any more information?
