Hydraulic 44 vs 41

I can't answer all of your questions, but may be able to help a little bit. To utilize the unused outside flanges on your #44 unit, you'll have to upgrade to a dual-valve setup commonly found in the D4 and D6 #44 units - the standard single valve that the D2's came with don't have anything plumbed to those outside ports. My book only lists the dual-valve units paired with the 37 gpm pump cartridge for the D4 and D6 tractors, but that doesn't mean you couldn't run a dual-valve assy. on a 25 gpm pump. The dual-spool units were commonly used for towed scrapers, industrial loader setups, or multiple towed implements where in those situations an operator may be running two sets of hydraulic cylinders at the same time, thus requiring a larger volume pump. In your case, if you put hydraulic tilt on your D2 you'll likely only be needing to use one spool at a time - either be just tilting or just raising/lowering - instead of prolonged simultaneous dual-function use. So the 25 gpm would probably do just fine.

The single and dual spool valves usually interchange easily, but you'll also need to swap the upper control lever assy. that sticks up through the top corner of the case, since the dual-spool valve uses a shaft inside a shaft in that spot to accomodate the two levers, one for each spool valve.

toolbar setups usually came 41 hydraulics. tobe big time hassle free stick with the 41. sell that 44 to help ur cash flow, especially if its complete.

If neither the #44 or #41 is a two valve unit you will need to plumb a diverter valve in to the system to get the tilt cylinder option. You could use the #44 pump system diverter valve or plumb in an aftermarket diverter valve. Understand that this is an either or arrangement and you would have to flip back and forth to alternate functions.