Hey Bill,
Go for it.
I did exactly that for my Camaro and SS Chevelle. Two engine stands, some 2x4 rectangular steel, a few square feet of 1/8" sheet, a chopsaw (miter), 6 castering wheels, a few nuts and bolts, and a mig welder.
6 hrs later I had an adjustable rotisserie.
The total materials including both engine stands cost me under 500 bucks.
Unlike Hershal's I tied my two stands together, with and adjustment for different length chassis at the bottom of the stands
Cheers,
Scott