Racing a Mach 427 I get ten minutes to a tank EASILY, and can push my pit stops significantly later than guys running VSPECs... Have done it several times. Ten minute pits, no problem. So trying to compare eight to 14(also something unrealistic on a regular basis) is pushing the comparison by a good margin.

Do the high end race engines get better fuel mileage? Sure, but it's not THAT big a deal from a VSPEC to a Mach 427, talking purely run-time.. And god knows Machs have better reps when it comes to conrods and bearings... (just to single out one, and possibly the most popular race 21's of the last five years..) The VSPEC might be better in other ways - idle, responsiveness, etc.. But it'd better be - it costs twice as much..(and there have been LOTS of guys with VSPEC's who never saw three gallons without catastrophic failure..)

The Mach 427 is MASSIVELY underrated. It'll hang in truggy with %75 of the so-called "race" engine 21s out there - in most significant categories. Though illegal, put it in a buggy and it'll hang speed-wise with even more..