A similar question was posed by a list member back in July 2006 and
here was my answer (love my Google Mail search!):

I've answered this question so many times I can just about do it from memory:

Vanagon Manual Transmission, 1981 Air Cooled

Bosch SR87X (091 911 023)
To Vin 25-B-093610

Bosch SR19X (091 911 023 A)
Vin 25-B-093610 to 25-B-152582

Bosch SR401X (025 911 023 A)
Vin 25-B-152583 onwards

The SR19X and SR401X are interchangeable as per Bosch & VW Factory
Parts Bulletins (the 401 replaced the 19)

Biggest differences are the "throw" of the starter gear (SR87 vs SR
19/401) and solenoid differences.  The solenoid on the SR401X is not
replaceable separately - starter with solenoid must be purchased.

Hope this answers your question
--
Jim Thompson
84 GL 1.9 "Gloria"
84 Westfalia 2.1 "Ole Putt"
73 K Ghia Coupe "Denise"
72 411 Station Wagon "Pug"
oldvolkshome@gmail.com
http://www.oldvolkshome.com
***********************************

On Nov 12, 2007 9:41 AM, neil N <musomuso@gmail.com> wrote:
> Hi all.
>
> Will a Bosch rebuilt starter from a 1981 air cooled manual
> transmission, work on a stock 1.9 WBX manual tranny bus?
>
> Bosch starter PN's:
>
> Bosch: SR19X
>
> VW PN: 001 211 251 (odd/unidentified character) 252
>
> other PN on it:
>
> 091 911 023A
>
>
>
> Thanks!
>
>
> Neil.
>
> --
> Neil Nicholson. 1981 Air Cooled Westfalia -
> "Jaco"  (Bustorius)
>
> http://web.mac.com/tubaneil