Thanks for the response. I would tend to agree about air in the lines, but... Two nights ago, I bench bled the rebuilt master prior to putting it in and then bled at the wheels (but forgot to bleed at the rear anti-lock brake modulator valve). Once I fired up the engine and the power brake booster was in play, I had a very low pedal that went to the floor and I had no brakes what so ever with out pumping the brakes (and even then I had a lot more stopping by downshifting). Last night I re-bled the master cylinder and then the rear anti-lock valve prior to bleeding at the rear and then the front brakes. I even raised the back end of the vehicle up so that the master cylinder was level when bleeding - seems that I read somewhere that this was needed on GM master cylinders that are not horizontal so that air could remain trapped in the master cylinder.

Any one else have any ideas / suggestions? I am desperate to get my car back on the road. Since I tend to do all my own service work, I don't have a mechanic that I am familiar with that I could drop this problem off on.