LOL that's OK.... I just report the numbers. You have a sense of humor and good perspective so you'll figure out what you need.... we're just stimulating the thought processes here!
BTW the lower ultimate miles on my SB 351C was due to starting with forged pistons with .004" bore clearance when set up, AND running a carb, which ends up with more richness at times in the cylinders. You're better off even just starting with the tighter piston clearance.
Keep us posted. I indeed want to see 20 mpg on that block of a van.