After sleeping on it, I'm starting to believe this is a shift linkage issue and has been all along. The clutch that I replaced wasn't worn all that much....I'll get it all back together later today and take it to the lake and see if I can do some more adjustments. It sounds like the clutch is just seating enough on the forward gear to work until pressure is applied and causing it to jerk in and out , if I can adjust the shift lever more, perhaps it will allow the clutch to stay in gear. I've done all the things you guys have suggested, so it's gotta be related to the linkage is my thinking. Like I said, I'm not a mechanic, but if all the parts are ok, then it must be in how they work.