The 68 440 darts can only run super stock in NHRA, and the 69 440 dart can run Stock class in NHRA. As to how fast or how slow they are, might want to check out Charlie smith's 69 dart (sold) and Steve Wann's 69 cuda both 440 cars built by Steve, dart held the NHRA "B" and "C" stock record at 10.18 & 10.39 et. Steve ran a 10.22 at Phoenix race a few weeks ago. I'm sure he still has some left in it !....LOL
