Slave adjustment

[October-1881]

I'm having problems with shifting my SPF 351. I'm new to this so cut me a little slack. I noticed the other day that it seemed like the clutch was slipping a little. I called Eric at Dynamic Motorsports and he suggested that I start diagnosing the problem by adjusting the rod on the slave unit. I put a vise grip on it and moved the locknut from almost all the way at the end to almost all the way nearest the cylinder. We took it out and all seemed fine. So yesterday I decided to take it out for a (200 mile) long drive. After driving about 2 hours...I stopped to get gas and take a little stretch. When I started it back up, it seemed to go into 1st kind of hard. When I drove away, I couldn't get it into any gear. Finally while coasting down the on ramp, I managed to get it into 4th. and drove the last 2 hours at 50 MPH in 4th. Is it possible that when the car gets warmed up the reaction of the slave unit changes? Is the adjustment that critical that I should be moving the locknut to about half way? It just doesn't make sense that it can work fine one time and be totally not working another
time. This is very frustrating because I have good mechanical knowledge (ex-construction worker) but have never done much with cars. Someone told me there may be air in the line and bleeding the thing is nearly inpossible. I live in a area where there is no-one that has the equipment or knowledge to repair it and I'm not nuts about trailering it 600 miles to Cincinnati. HELP