This has been done and does work. Kind of. I think it was Volvo or maybe Volkswagen that had a vacuum advance AND boost retard distributor. But with the amount of people that barely understand how mechanical advance and vacuum advance actually work (let alone tune them), an MSD box and a dial on the dash is much safer and easier to make right.
Probably, but WE could do it I bet. I would want to find an adjustable vacuum advance that had the highest amount of advance I could find. That would give a lot of adjustment. It would certainly be interesting to try.
