Hy Mt. Tam Trucker, P.T.O.s are application specific, that is there are different gears to fit different transmissions. Some are single speed, some are two speed, some are reversable. Are there any ID tags on the ones you picked up? The mounting holes/pattern is an S.A.E. standard size, so one P.T.O. housing will fit any transmission, provided it has the correct gear installed for that transmission. You must shim the P.T.O. to the transmission when you install it, for proper gear backlash. they provide gaskets of different thicknesses for that purpose. Is there a truck tranny shop or power transmission shop in your area, or a truck wrecker that has been around for awhile, they should be able to help you get the correct gear for your P.T.O., or to identify the ones you already have, hope that helps.
