I like the Bentley's or the Factory AKD-4021 manuals. Haynes is okay. The basics are in the manuals. But, most of what I've learned in 30+ years rebuilding the ribcase gearboxes isn't in the manual anyway. If you have rebuilt any transmissions in the past, you'll figure your way around the BLMC box pretty quick. Example of what is not in the manual; If you mix and match pieces, then be sure to shim the travel of 1st gear. Otherwise, the detent balls can pop out if you push the gear lever past the shift rail detent and the box will stick in 1st gear. Especially true if you have a worn shift fork. There are valve spring shims that work fine as spacers to limit the travel. Stromberg carb float adjustment shims work too. Shift forks can be tightened up in a vise by squeezing. Not too much, but just a snugging up. Bent coat hanger wires, small flat blade screw drivers and X-acto knives with the blades turned backwards work great as tools to put the retaining plates back on top of the gears. My substitutes for the factory tools. These kinds of things aren't in any manuals.
HTH,
Mike Miller
35+ Years of LBC Addiction