383 build for efficiency

Why a TBI EFI? From what I have been reading TPI has many advantages over a "self learning TBI".
OD...assuming an auto? A lock up convertor will drop your rpm a bit...more importantly will eliminate all efficiency killing slippage at speed.
Have always wondered how a stroked 400, say a 451 would run if it were treated to some of the modern day stuff. Similar to what you are talking about...a hydraulic roller designed for EFI, perhaps use some of the modern coating technology.
I do know of someone that had a 572" HEMI. Was over 700hp. No OD, FAST EFI...got close to 14mpg on the freeway. Hmmm...