From personal experience having seen guys buy an individuals rebuild I would be a little cautious on buying an engine that I couldn't at least hear run (and more preferably drive). If it's a fresh engine, I would check with the machine shop who did the work and also find out who did the assembly.

One particular exampe that comes to mind is a customer who bought a never fired engine that someone (who was moving) had for sale. The machine work had been done by a good local machine shop and the owner had done the assembly himself. I was paid to tear the engine down and inspect it before it went into the car. The guy who built it did pretty good except for one little thing, HE PUT THE MAIN BEARINGS IN UPSIDE DOWN. Had we fired the engine it would have shown great oil pressure up till the moment it seized which would have been almost immediatly after it started.

....."Use the BB or even a 454 if you want balls..it'll bolt right in to the 350 mounts and tranny too..."

What streets says about the BB is true but really not as simple or cheap as it sounds. You will also need to use heavier front springs, build a new exhaust, find the brackets for the accessories and likely need a bigger radiator.

On the other hand, building a 383 stroker will not be as cheap as it sounds either. To do it right the block will need to be clearanced for the crank throws, bored, vatted, new cam bearings installed, and the heads gone through.

Good luck on which ever way you decide to go.