box the frame? no, but a 6-point rollbar or cage would stiffen up the whole mess so that you could be consistent at the track. Get yourself a NHRA rulebook to learn how to build it.

Basically the only thing that is different between a 350 and a 383 stroker is the crank, pistons, damper and flexplate.

Here's a link to the S10V8 forum. There are quite a few forums dedicated to this swap. Just do a search for S10V8.....
http://www.s10v8.com/forum.php