Just my 2 cents - Don't guess at engine, pump, ram sizes etc. Getting one of these built & having it not work good is a waste of time and $$$$$$$. There are dozens of manufactered ones built, check them all out. Google, ebay, whatever. Find out what they use for components and get as close as you can. They've already done the engineering, made the mistakes & [hopefully] corrected them. Some 10 years ago I built a small crane for my F350, I got info. from everyplace that I could find, then built. Got it done & it worked - Still does too. Cutting, drilling, & welding steel takes too much time to do it twice. 10+ years ago I watched a Multi-Tek processor at a show in Springfield Ma. - It worked slick - If there was one I was going to "borrow" ideas from, it'd be that one.