My Duster ran a best of 12.67 at 107 mph with a 1.9 sixty foot last summer. I want to optimize my combo during the off season. Currently the car has a 741 case with a broken Sure-Grip and 3.91 gear (Found out the Sure-Grip was broke at Milans all Mopar day. Embarrassing to say the least). I am definitely going to upgrade to a 742 case with a spool. I want to turn 6500 rpm through the traps and I run a 27" tall tire. I am thinking 4.30's will be good. You guys have never steered me wrong so I thought I would consult the experts before I made a move.

Ryan "Bigs" '73 Duster (BLKDUST) - Black, 100% factory sheet metal, flat hood, 346 cid, J Heads, and a bench seat. http://s268.photobucket.com/albums/jj1/bigsbigelow/ Best to date: 12.40 @ 109 mph