The pump I used was a Perkins prima from a rover montego turbo, I have a couple of those on the shelf and the power output of the prima is about 90hp or so, depending on configuration, so it seemed to me to be a fairly good match to start with. Also that pump has the adjustable mounting for timing, some engines have a fixed pump and Vernier pulley, which is great when you know exactly where it should be with a dial gauge for static timing, but not so convenient for experimental adjustments on a project like this. With the prima pump I can just slacken a couple of 13mm nuts and roll the pump a bit to try a new timing position, which you really need to do whilst driving, just repeatedly stopping and making small adjustments until youve got it just right based on sound of the engine, clean burn and responsiveness.
The prima pump has a long nose which is good for this but unfortunately slightly too long to carry the original k9k pulley. So I shortened the pump nose by 3mm which involved a little bit of lathe work and also dismantling and rebuilding the pump. I also had to shorten the body of the k9k pulley, again on the lathe.
I think the transit 2.5di bosch pump may be a better donor, I'm not sure as I don't actually have one to measure, I'm just judging from photographs. It would be nice to find out. That method too would involve dismantling and rebuilding the pump though, maybe not quite as extensively as my method, but you would need to fit an LDA turbo compensator top assembly from another turbo pump as the transit di is non turbo. A pump from a turbo vauxhall astra might also be a good option, 1.7litre I think from memory, ive never had one though and i suspect it would have a 17mm shaft.
There's a number of pumps that might be a good fit but would have 17mm shafts so you would have to make some kind of pulley adapter between a hub that fits the 17mm pump shaft and a k9k pump pulley or possibly the Vernier camshaft pulley might be better, but if you used the camshaft pulley your 'adapter' would need to include the little inside edge standup that the k9k pump pulley has to prevent the belt running in towards the engine. If everything is correct the belt shouldn't run against that but it is there to prevent a calamity.
The bracket is a steel fabrication, 8mm plate with a couple of lugs welded on to bolt it to the cylinder head picking up the two 8mm bolt holes nearest the timing cover. I had a couple of goes at it, i first made one i could easily adjust by bolting it together in different positions in order to find the best location for the pump.
Now that everything clearly works I have to make another bracket to support the back of the pump, the two 8mm bolt holes that hold the common rail accumulator are very conveniently placed for that.