I am in the middle of a brake upgrade thats gone cause me a bald spot.. I recently installed a 14 ff w/ disk brakes. The brakes felt like they just wernt getting enough fluid, so, I purchased a 1 ton master cylinder. I pull my master cylinder (1/2 ton) and make up some new hard lines to the praportioning valve.. I get the whole thing bench bleed and try to install the new 1 ton master cylinder to my 1/2 ton brake booster. Hmmmmm, first snag.. the plunger in the 1/2 ton master cylinder is hollowed out to allow the vacuum booster rod to ride inside of it. The one ton is solid with a small indentation. Ok.. So I fork out a 140 bucks for a 1 ton vacuum brake booster...this thing looks perfect for the master cylinder. The rod looks right ..except it wasnt adjustable like the documentation with the master cylinder ... Snag# 2 .. II have a first gen truck... you dont want to buy a first gen booster, trust me. The second gen booster, unfortunetly, will not bolt into my first gen truck without major sugery.. So I purchase a 1 ton first gen brake booster that now has the proper adjustable pushrod ... While at the part store I asked to see the master cylinder for a 1 ton 72 truck.. It is exactly the master cylinder I have. Now, the 1 ton booster will bolt into my truck with a minor bracket adjustment, I think.. My measuring tape says my mounting brackeet is too tall now.. My question is how far is the vaccum booster supposed to depress the piston in the master cylinder. When I checked the master cylinder on the booster, with the adjustment at its shortest setting, it stuffed the piston in alot.. near an inch.. from what I'm reading it is supposed to "preload" but gees an inch.. tomarrow it looks like Im going to be sick putting my half ton setup back on while I work out the bracket issue.. did any of that make sense?