Greg, give me a call and let me know of your travel plans. As always, we'll buy you a good meal if you come to town. 931-378-2060.
I went to a few websites this morning and many of them say a bad GM booster will, amongst other things, cause the pedal to go to the floor. There is an obvious, loud suction sound coming from the (booster?) when brakes are applied.
'68 428 HO M3 Monster, 4-on-the-floor! Need I say more?