That looks a lot like what I'm building in a shade tree shop in south central Tennessee- - - - - -except I'll be using mostly "off the shelf" parts instead of going with the "There's no substitute for cubic dollars" approach. My engine will have a longer stroke, and displace around 300 cubic inches. I still believe I can make a twin cam 24 valve cylinder head from an Atlas six work with a stovebolt block. For a somewhat less radical approach, the forged steel camshaft for a 216 can be reground to work with roller lifters for a MOPAR big block V8. It's also possible to put roller bearings into stock stovebolt rocker arms if one chooses to stay with the original cylinder head design.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!