The later model Dual or Triple pulley water pumps for Fox 3.3's ran the same length water pump as the XW-XF, 4-1/2" (or 114 mm), and the US 250. .
This ^ is
rickwrench's website photo of the later Fox water pump on the left, verses the earlier Round body 144/170/200 water pump (same as Aussie XK/XL/XM/XP/XR)
All the early Us 60-pre US 250 and XK-XR stuff was 4"(101.6 mm). The Aussies then did add some 5/16" (8mm) relief work with the tall deck 188/200/221/250 engines. The early balancer scrapes the sump, practically, and when its upsized to 6-7/8", it was too close to the cork gasket at the front part of the sump. RTV has fixed all that.
The US 250 lead the way to the 4-1/2" long water pump, and to make it easier to swap all the ancillarry drives, the small deck US 200 then got equiped with a 4-1/2" pump, a different kind, but 4-1/2" none the less.
This ^ is
rickwrench's website photo.
The early stuff on the US 1960 to pre US 250 engines used the common approx 6" balancer as was used on the XK-XR, it is all set back, right hard against the engine blocks sump.
This ^ is
rickwrench's website photo.
The Fox three grove used the same size balancer, in the same postion, but with a triple pulley system, and it was set right back 5/16" (8mm), with the sump relieved to avoid it rubbing the balancer.
There were therefore 5-3/4 and then 6-1/4" small six versions.
Its the Aussie stuff that was set forward 5/16" 8mm.
This ^ is balldrick's photobicket shot of the AussieHB1432N balancer requires a little work on the water pump pulley it the stock water pump is used. .
If you are able to use the larger Aussie noiminal 6-7/8" (174 mm actually) balancer, it just requires an 5/16" metal spacer to shift everything from the water pump into alignment.
The distance from the crank to the water pump on 9.38" deck 200/250 engines is about 6-7/8", so the biggest balancer you can run is 6.85" (174 mm), and the largest water pump pulley before collision is the 6-11/16" (170mm), with just a 3/16" (4.8mm) gap.
On my 81 3.3 Mustang, there is 6" from the water pump to the crank centreline, and the same 3/16"gap between the 6-1/4" harmonic balancer and the 5-3/8" water pump pulley. When you go up to the 6.85" harmonic balancer, then you have to go down to a 4-25/32" water pump pulley at the most. And for sure, the harmonic balancer is 5/16" further out than the stock 200 blancer. But you just add that in a metal spacer, or scratch build a water pump pulley to suit.
rickwrench did a nice 5" twin belt pulley for his short nose 4" 200 water pump.
You have to make one even smaller than this, with ribs to suit the kind of serpentine belt you are using. Due to the portrusion, without an added spacer, 1.9625" (49.85 mm) is as deep as you can go from the front face of the pulley to the back if its machined this way, as the 200 water pumps lower radiator hose interfers,
http://www.v8alfa.com/images-sounds/pulley.pdf
See
viewtopic.php?f=1&t=9676
It's just a case or reworking what is there to suit your application.
As for pictures, I've got bucket loads showing the minute differences, but what is above is enough.