Back in the early 80's, a buddy of mine had a chance to buy a 70 R/T with a 440-6pack, once we got the bugs worked out a little with the carbs we took it to the track. With a 4-speed & Mickey Thompson Indy Profile rear tires we got it to do 13.3, beating a Hemi Road Runner to his 13.5 with slicks (No drag radials then). This was in fall in the northeast.
The old Hemis were consistant 13 second cars.