Find an original GM service manual. There are bunches of them on Ebay, at some very reasonable prices. The TH-400 was produced from the mid-1960's to the mid-1980's with very few internal changes. It's also the basic gear train for the current 4L-80 overdrive transmission. It uses an electric solenoid for the 3-2 kickdown, and one early model called the Super-Turbine 400 used a variable-pitch stator in the torque converter. You'll need some dedicated assembly tools, as some of the clutch piston seals are VERY difficult to install without cutting the seal lips. Also watch out for a couple of identical-diameter snap rings that can be installed in the wrong position. If the snap ring with the tapered edge is installed to retain the intermediate clutch pressure plate in the case, you'll get exactly one 1-2 shift and the ring will dislodge. Always use the square-cornered ring to hold the intermediate clutch plates in place! Don't ask me how I know that!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
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