tranmission interchange

I have a 78 510 wagon with an automatic transmission that won't shift into 2nd gear. I'm interested in converting it to a manual transmission, preferably a 5 sp. Talking to wrecking yards, their interchange books say only 78-79 will interchange. I'm new to Datsuns having primarily delt with Ford stuff. I understand that I have a L20B motor, that has alot in common w/ the "L" series of motors. I think I've seen that the L20B has a six bolt flywheel instead of a 5 bolt found in L16 and L18. What issues will I have with finding a transmission to interchange? Are the bellhousings common throughout the L series? Are there bigger or smaller sized flywheels, are they externally balanced or is the engine internally balanced or maybe balanced at the harmonic balancer? I realize that I need to come up w/ a hydraulic clutch setup. Help me learn whats involved and what I need to acquire.

internally balanced
different flywheel sizes and throw-out bearing lengths
any l-series tranny will bolt up
or you could swap bellhousings and use a NAPS-Z tranny
you'll need to find a clutch pedal for your car, and find a way to mount the master...

oh yeah, L20b had a 6-bolt flywheel but the racey L18's did too
I'm not sure what the Z used, I think 6-bolt, but it's big
try to find a 200mm, 6-bolt f/w

Your best bet would be to find another 510 wagon with manual transmission and same engine, grab everything that you may need from it, which would be the flywheel, the clutch petal, brake petal (smaller in manual transmission cars), clutch master and the reservoir, slave cylinder and of course the transmission which must include its mount. However if you should to go with other Datsun/Nissan cars. Your L20B will accept any transmissions from cars or trucks that have L series engine; The 280ZX cars would be your best choice because they came with 5-speed manual transmission and were built to last. While man-handling the transmission from 280ZX, grab the flywheel too; it's a lighter flywheel and it has 6 bolts pattern same as your wagon. As far as installing the clutch and brake petal and the clutch master, your wagon should already have spots that were predesign from the factory. They shoud all bolt up. You may need to cut a hole on your floorboard for the stickshift to poke through. After everything is in place, you also may need to custom made a driveshaft to fit the new transmission to your wagon as well. Sounds like fun...good luck!

Garagetuner1, Seattle, WA