Ladder bars/stock frame/rear coilover length?

There's not a lot of room so I know the options are limited. Trying to get an idea of rear coilover shock length on a '73 Dart with ladder bars and stock frame. Anybody running a similar set up?

I have these on all 3 cars..they are relabeled Qa1 shocks...
JEGS Performance Products 64905: Double Adjustable Coil-Over Front or Rear Shock Compressed Height: 11-5/8" | JEGS

I use adjustable mounts on the lower mounts...also use 110 lbs springs......you will need to weld new upper shock support tube across the frame rails.....