[s-cars] CPS mounting boss changes in early 92 - 93 AANs

[David Forgie]

As you know, the cam position sensor (Hall sender) on the AAN engine is typically mounted
on the head, behind the exhaust cam sprocket.  Exceptions are the very early AAN's that used 
a vestigial (tuna can) "distributor" at the back side (intake side of the engine), driven off a gear
on end of the intake cam. That was a carry-over from the 7A and 3B engines 
(which had full distributors).

Up until yesterday, I always thought that when the CPS moved from the tuna can, to behind the
cam sprocket, the mounting boss was cast into the head.  NOT so.  There is evidence (as shown
in the link below) that the factory used up some 3B heads by supplying a separate mounting boss
that was bolted to the head (and then the CPS was bolted to it).  I am curious as to when this 
practise started and stopped, based on build date.  So if you have such a non-cast boss, can you
please post your car's build date?  (Thanks).

Photo of the add-on CPS boss (note - no PN in the FA for this):

http://forums.audiworld.com/s4s6/msgs/231574.phtml

Here is a photo of the "normal" cast CPS-mounting boss:

http://forums.audiworld.com/s4s6/msgs/231588.phtml

This all came up because a fellow in Norway has developed an add-on boss that will permit
7A heads to be used with normal AAN CPSs.

Dave F.