I took some pictures last night but they came out blurry ... I will retake tonight.
The T4 case pickup tube diameter at the entrance to the pump is 12mm dia, and the 45 deg passage to the stock oil filter is 10mm dia.
On the pump, the intake to the scavenge side is 15mm dia and the output to the stock oil filter location is 12mm, so the pump has inlet/outlet bigger than the passages in the T4 case.
Due to this, the pump passages line up well with the case passages, if you really wanted to, you could try to open up the case passages to match the pump but I will not. In the pics you can fully see the case passage from the stock pickup tube location through the pump scavange hole (15mm dia) and when I stick a pencil in from the stock oil filter location, you can see it through the pump transfer port (12mm dia).
From measurements with the stock T4 pump, the body of the CB pump is roughly the same height at the drive boss, and it fit the case nicely without the drive tange .. remember, I am using a stock cam with rivets so I could measure no clearance issues.
To get the drive tange to engage the cam, I pressed the gears further onto the drive shaft with a vise and some sockets, about 3mm total, in effect making the drive tange shorter. I can turn over the engine with the starter (no coil wire attached !) and pump installed and when I pulled the pump, there is no contact with the cam rivets. I seem to have about 1mm clearance from the rivets to any location on the pump.
The only item I have to address is to machine about 3mm from the driveshaft that now sticks into the cover plate, essencially making the whole drive tange 3mm shorter. I did not want to touch the opposite side of the drive that engages the cam slot. I will press the gears off and do this on the weekend.
The pump clears the BAS header by about 13mm so no clearance issues ! and no issues with the pump input/output touching the case. If you have a rear engine hanger bar, you will not be able to fit this pump. I'm using a Cup brace so no issues. Not sure if this pump will fit in a 914.
So looks like I'm good to go with the installation. Just need to install the tank, wait for the fittings/hose to show up, plumb the system and we're on the road for a test. Good thing the weather here is still crappy
Hope to be driving in early April.
Sandeep