Installed the mounts in the down position.
Distance between my shock mounts are 21".
Truck is sitting on wheels, but minus the weight for a wood bed.
The rear shocks are Monroe 33049. They measure about 14" compressed, to 23" extended to the very end, when off the vehicle.
The 23" shock just looked over extended at 21". I guess the weight for the wood bed will bring the distance a little closer.
Thanks for the input.