A12, 4.56 axle, 9” converter, stock blueprinted short block and heads with old cheater cam, .440” / .470” hydraulic, through flowmasters. 3725 pounds on the starting line, last time out (2005) 11.28. I drive it on the street as it is.
For you, change the axle ratio, use a good 10” converter, lose some et. Use a better cam and heads and get more back than you lost.