Need some clutch help please.

[retodd7711]

Need a little help on My '62 v6 305.
I replaced the slave cylinder and I just can't get it adjusted right.
Before the slave took a dump the clutch was tight and no slip.
Contact point was real low and when you released the pedal it would snap right back up. It would fry the tires and launch good.
I have bled the slave several times and today worked on adjusting it.
The pedal releases real slow. the contact point is real high.
I had it adjusted too far and the clutch was slipping( motor revving in 3rd and 4th)
I adjusted it back and got it to grab, but the contact point is really high.
I went for a ride and it was good and tight.
After 3-4 miles it the contact point became "mushy"
Grab, chatter, grab, try to stall.
I dumped the clutch and the truck just kinda took off.
I'm almost out of adjustment and the contact point is almost at the top of pedal travel.
What would cause this drastic change?
I'm adjusting the clutch at the rod on the slave cylinder.
All help appreciated.
Todd