I'm fairly sure the gearbox crossmember mounting points are wider on the XA (XB XC XD also same)
I only assume this due to i think i've had both and one didn't fit. 

@Thom may know for certain. 

What are the differences between xw xy and xa xb gerbox cross mounts. I an particulately interested in the width appart of the two end mount holes and of the recesses for exhaust pipes if they are wider in xa xb versus xw xy. Just cant see the differences, if any, but thought the outside mount holes or exhaust releifs wre wider in xa xb.

awesome.....got one of E-bay for 50 bucks , Might look at getting a brass one later on down the track .   Thank's Gent's

I was thinking of the reliable ones in the Ford Traders.

at least it's not the AU one that's made of the crappiest plastic it crumbles as soon as you look at it (when it's this old)  that said, they can still be cracked on XF, probably Qld climate would be more of an issue.  XD and XE had rubber hoses that fell apart instead, so not sure what i'd prefer of the x series type. 

Those stupid vacuum lines running inside the dash, think I may have a leak under there somewhere. . Something to investigate when I get back home.   Give me the good old fashion wire control cables anytime.

@Mick.G here's a link to autobarn for the expensive one at autobarn.. (call them to be sure they have it before going down there i'd say)

https://autobarn.com.au/ab/Autobarn-Category/Shop-our-Full-Range-by-Brand-at-Autobarn/Kilkenny/Kilkenny-Castings-To-Suit-Ford-Adaptor-[TBi]-Vacuum-Tree---KC137/p/SP66052?srsltid=AfmBOopr1HxNKshSCbhONTv6N4p97u12iidt1foW-AjsPSac5-3jXS5C
I'm fairly sure there's cheaper versions with just the brake booster outlet, and one other vacuum outlet for heater etc, you could then T piece that into 2 spots if needed. 

Kilkenny Castings, make brass versions I believe?

this one is sold, 
but @SPArKy_Dave may know if anyone stocks them anymore. 

https://www.justparts.com.au/parts-for-sale/ford-falcon-xe-4-1l-manifold-vacuum-outlet-2-port/JPW3972384

I've never bought from this place, just googled
falcon XF vacuum tree ( one with the brake booster hose like yours has one bigger outlet )




https://srpauto.com.au/ford-parts/engine/manifold-fitting-brass-xc-falcon/