65 Dart 273 to 340 ?

If I'm not mistaken,The early small blocks {67 and earlier I think}had a smaller crank register for the converter hub.Someone on this website sold me a spacer to take up the difference in the crank, but I ended up going with the four speed.Was the best drivetrain choice I made,because pedal cars are much more fun !! :burnout: 8) . . . . . and yes exhaust choices are a big factor