California ECM question

[drewniverse]

I was reading on the bay thread (RIP Karl) and I found one that contained ECM part numbers and what their letter designators designated for bay buses.

http://www.thesamba.com/vw/forum/viewtopic.php?t=301261&postdays=0&postorder=asc&start=0

In the list I found this...

Vanagon:

California Models:
071-906-021B All Transmissions 1980-1983 (071 plain and 071 E subbed to the 071B!)

I have a 1982 vanagon and a 071B that is outputting .55v (it should be 1v) to the 02 sensor so it's causing it to run badly (on 3 cylinders.) I temporarily fixed it by grounding the 02 sensor out but now I'm gross polluting and it's still running a little bad at speed.

My question is, what does this mean '071 plain and 071 E subbed to 071B!'

Would I be able to use a 071 plain or 071 E? I can find a 071 plain on eBay for $100 but I'm apprehensive to buy it since I don't know if it will work or not.

Any answers are greatly appreciated, thank you!

EDIT ::: I found the answers in the type2 library. Thanks again Karl, your legacy lives on!
http://www.type2.com/library/fuel/ecuswap.htm

This is a very interesting read...