Measure everything twice amd take good notes as you go. Also I don't think it'll need 4.56 gears. My street/strip Dart is 3260# with me in it, 408, 10.9-1 with a flat solid cam and ported edlebrocks runs high 6.50 in good air and high 6.60s in street trim in the heat with 4.10 gears and a 28" tall radial.
