they are not maintenance adjustable on the th400
There is no adjustment for the bands on a Chevy automatic transmission. They self adjust as the bands wear.
as long as it is a chevy bolt pattern th400
It can be done, yes.
same bolt pattern if the 4l60e was behind a v8 or 4.3and the th400 was from a chevy and not a (bpo or caddy )
No.
Automatics would include th350, th400, or the 700r4, if you want a overdrive.
just about any Chevy trans, a TH350 or a TH400 are the most common and will both fit. as far as engines and transmissions with Chevy's there just about all interchangeable without to much messing around. only difference with a TH350 to a TH400 is that a 400 will take higher horsepower/torque. but for most stock applications a TH350 will be fine , oh and the TH400's are slightly longer to.
Sure, preferably a short tail TH 400 with the Chevy/Buick bolt pattern.
i suggest you either adjust the bands or get a new transmission.
you can purchase an atsg manual, ron session th400 book or other print. google search for it or go to helpwrench.com and find an exploded view if one there with diagrams.
1 and a half to 2 qts