Start with a RB crankshaft offset ground to have BB Chevy rod journal sizes and a 3.91 stroke, bore the block enough to straighten the bores up real well and have the mains and counterweights turn down on that crank to clear the 383 block
![scope scope](/ubbthreads/images/graemlins/custom/scope.gif)
That should push your passengers WAY Back in thier seats
![boogie boogie](/ubbthreads/images/graemlins/custom/boogie.gif)
You will probally have to have a custom piston made for this deal, make sure and figure out exactly what compression ratio with which set of heads you want before ordering the pistons
![up up](/ubbthreads/images/graemlins/custom/thumbs_up.gif)
Using a BB Chevy type H beam steel rod work very well in these appications also