Don't sell it. If you're frustrated, just put it in storage until you're ready to work on it again. I almost sold mine last weekend, but the guy's wife said "NO". I think that was an omen. I parked mine 7 years ago and last year got a bug up my a$$ and built a new motor, p90, custom cam, Dellortos, the whole nine. Then I parked it again. I started it last weekend and that was all I needed to want to work on it again.
Long story short...don't sell it!