Brakes bled and pedal goes to the floor but I do stop... sort of.

[broncomatt]

To check for an obstuction open a rear bleeder, put a few feet of clear hose over the bleeder so the fluid goes up the hose. Check the rear axle first, then the front. We call that a one man bleeder. Clear fluid and if there are any bubbles they will go up the hose.
To be honest it reminds me of some of the master cyl swaps I have tried. If you get the wrong one (for smaller or lager rear wheel cyls) it can make your pedal travel down allot further to stop the truck. Keep in mind the master cyl is supposed to be matched to the rear wheel cyl and front (calipers or wheel cyl). If its incorrect it can give either a hard pedal with a short stroke or a long stroke and a soft feel. Wheel cyls are diffrent depending on the axle size (load rating). Double check what parts you have put in.