[Healeys] AEC 3475? laygear?

[Mark Bradakis]

I have this item in my garage, been gathering dust for many years.  I 
would love to see it go to a good home, hopefully get some side shift 
transmission back on the road.  It has AEC 3475 written on the side. 
But from what I have found out is that the AEC 3475 has a bore of 0.855 
inches.  This gear has a bore close to 1 inch, like 0.990, give or take.
And the AEC 3649 laygear is listed as having a bore of 0.985 inches. 
Which is the gear fitted to BN7 side shift gearboxes, as I recall.

So, wonder exactly what I have here?  I want to auction it on Ebay, but 
I want to be sure about what exactly I am offering.  In case you are 
wondering, it has 25 teeth on the big gear at the end, which I assume is 
the end closer to the motor, and meshes with the input shaft gear.

So what is it I have here?  An AEC 3475 as labeled, or an AEC 3649 which 
the layshaft bore would seem to imply?

As some of you are aware, I am a Triumph guy, I know very little about 
Healeys of any sort.  Anybody want an NOS laygear of unknown origin and 
unknown fitment?

mjb.

ps: If you are on the shop talk list, you probably have seen my query 
about my Mitutoyo digital calipers, which are not working.  Otherwise I 
would have a more exact measurement of the layshaft bore of the gear.