I heard that alot of late 80's & early 90's Ford trucks had a problem with a "long" brake pedal. The vehicle would always stop but you ended up with the pedal almost to the floor. Well my 88 E250 van has done this since I bought it back in 2002. I was also told that Ford came out with a revised master cylinder to cure this problem.

The main question here is, if this is true would I have to buy a MC from Ford or are all of the MC's available from the after market "revised"?
And what was "revised"?