I got a 79 ScoutII, converted to front k20 calipers and the dual piston calipers in the back. Question is I need to push alot of fluid(or do I really??) so I see alot of hydroboost available on ebay and was wondering should I just grab any one that works and bolt a late model disc/disc mastercylinder to it? Do I need a prop valve? Seems the hydroboosts from cars have the better chance the pushrods fit without much mod or are adjustible.