Having a new set of heads like the Airwolf 220 small block heads I think greatly dimishes the "need" to do a big block A body, you basically have an affordable small block head that flows comparable to a mildly well ported Edelbrock, so that to my thinking means a 416 small block should have very comparable power to weight performance to a 449-451 inch big block of comparable head flow.

For anybody who has not driven a mild high torque moderate rpm stroker small block torque motor, it drives as well or better than a comparable or slightly higher cube big block. Torque is cubes, power is the heads but power to weight ratios when equal in terms of torque curves almost always favor the lighter of the 2 combinations in terms of overall driving satisfaction. Plus regardless of p/w a lighter car reacts more predictably and stops quicker.

another option people are yakkin about...

you take a 318, preferably one of the older truck versions with a forged crank. you get a cheap ebay GT45 turbo that just happens to be the right size for a 318 about $250. grab some 2.02 heads, compression can be 8:1 or so, dont matter. should not be higher. you use truck exhaust manifolds turned around backwards. a little bit of fab work. you can use an E85 blow thru carb for some detonation resistance. some sort of intercooler & misc hardware. run 8lbs of boost. quick/cheap 500-600hp lol.