[Vwdiesel] 81 Head Bolts

[Rudy]

I took the Head off an 81 Rabbit 1.6l engine today, the Head Bolts are 12mm
threads, 12 point socket head like 12mm stretch bolts but the washers are
9/16" thick and they slide right off the Bolt like the 11mm bolts.  The
threads don't go as high as the later bolts and there is a shoulder to fit
the washer under the head of the bolt.
 
I tried new 12mm bolts and they bottom out before they come tight.
 
When I removed them they weren't tight like a stretch bolt, more like an
11mm bolt.  I'm wondering if this could be something from VW's transition
from 11 to 12mm bolts or if this is something to do with the head requiring
shorter bolts.
 
Has anyone seen these before or know if VW made a 12mm thread non stretch
bolt?
 
Rudy