Homemade Tilting dump, transfer case speeds?

Now that my Case W3 Backhoe is functioning well I am going to get my 85 Chev 4x4 1 ton dually working with a functioning tilt dump deck. I want pick-up dump to be used with my backhoe for summer 2017. The truck used to be a tow truck and it has a pto on np205 transfer case. Truck has the sm465 4 speed with bull low.

The used hydraulic gear pump has spool valves, hydraulic lines, and pto driveshaft. Pump is a commercial shearing gear pump (ID tag model: P2300 VCR 311) and I still have to figure out its gpm. Serial number on pump id tag is 5771, casting number on pump is SA 1686. It came from a old wood chip truck that had a telescoping ram that pushed the chips out of the truck. I researched that I can measure pump housing width and gear size in side of pump to figure out its gpm. My cylinder for dump is 4" OD", 2" dia ram, cylinder length 17.5" and extends 29.25". I have detailed plans to fab and weld a tilt mechanism, kinda like a rolling jack set-up. I could post web site name that I got dump plans from yet don't to get my post deleted for advertising. I'm hoping I can run t-case at a low speed if pump is rated for high gpm. Does anyone here know how to decipher model number of pump or have data on typical np205 transfer case speeds? I expect you use tranny to control speed of t-case??

Any help would be appreciated. I may have to end up buying a different pump, possibly 12 volt too, with its own reservoir.

There's a number of unknowns here... even if you calculate pump displacement, you still need to know how fast it turns, and I would suspect that there's a variety of PTO pump drive adapters for that transfer case with different gear ratios.

Can you borrow Flo-Rater and verify what GPM's it puts out at various engine speeds and "gears" and see if any are in a range usable for your project?

I guess I'm more ruff and ready. I'd start in low gear and if it isn't fast enough for you, go up a gear until you're happy

Ok. Thanks guys. Is a flo-rater a tool?

<img src = "http://www.ihcubcadet.com/forum/messages/106/181218.jpg">

This is the old classic "flo-rater" made by OTC. About every implement dealer's shop or independent tractor shop used to have 'em, they are used to test the flow rate and pressure capabilities of a hydraulic system.

I thought you might be lucky and know where you could use or borrow one in your area.

Below is a modern version, the flowmeter is at the right of the valve.

<img src = "https://www.tractorjoe.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/HCI/830463-hydraulic-flow-rater.jpg">

Thanks Bob. I'll call my local tractor shop and parts store to see if they rent one or if I can buy one.