Pre- or post-'70 didn't seem to matter much in the old days. Anyone I knew who had a Hemi (including two Challenger owners) practically lived under their hoods. Most of the time, the adjustments were carburetor related. Apparently, the vibration would screw up the settings deluxe. That's why I've always favored the 440 Magnum and was naturally wary when Dodge reintroduced the Hemi name. To me, it was NOT a name I'd have put on a new engine. Of course, I also wouldn't have tried calling what in effect was a 318 a Magnum, either.