For $1K, I say grab it, sit on it, continue as planned with Doby and your truck for your kiddo. Wouldnt risk a teen wrecking what appears to be a super straight platform for a "dream build" of yours. It may not be fast, but I bet the brakes on it are a joke, and beg for rear ending or not slowing quick enough for a curve in the road. Seeing what youre doing with Doby while "in a hurry," that '83 could be a super rare show car down the road... That is just my thinking.
Edit: Dave, with your skill level and a couple/few years, that '83 could be a magazine car. Thats all I mean.