Bosch Distributor distributor identification

Evening all, just discovered this forum and this is my first post.

I have a DS block in my '84 Audi B2 Coupe that was originally fitted with the PIerburg carb and pea-shotter exhaust giving 90PK. I have been running a DMTL and a larger bore exhaust system from the 112hp GTE for nearly 10 years . Dizzy is an 026 905 205 J timed at the flywheel 18 degrees with hose on. Vacuum pot is good. Petrol is 95RON and I don't get pre-ignition. The engine has done at least 250000km, will have lost some compression but it generally runs great and gives pretty good millage. I have an O2 sensor permanently fitted and have reamed and fine tuned jets over the year.

After reading the recent post on Bosch dizzy I read that the AK or AA dizzy is the one to have, not my 'J' dizzy. I saw some vacuum maps and was wondering if anybody had insights into the 3 dizzys I have here in my personal stash from different B2 Audis:
1. 026 905 205 J
2. 026 905 205 F
3. 026 905 205 A

And how they compare with the AK/AA. I no longer have Etka and although I am willing to swap out and try i'd like to have some basic timing set up figures.

Thanks, Stuart

 

Thank you very much. I am very greatful.

I made a typo in the F model. It is:
026 905 206F

Bosch numbers Z415 then followed by 0 237 020 117

Is there any chance that you could pull up the vacuum specs (advance specs of vacuum and centrofugal at with different rpms)? I would like to get my head around the differences and rty and understand what the advance is under different conditions.