73' B3 340 Duster pro touring build

Old Man Mopar said
It is clear to see in Ross's K-frame pics above how this special
version of the HDK has the side rails raised in relation to the
mounting pads so as to raise the powertrain and thus lower
the car. Ross has cut and raised the tunnel in the unit body
to accomodate this radical mod.

the primary reason for raising the rails is for tie rod clearance since everything else is raised ..... all at NO ADDITIONAL cost from HDK

while Ross's doesn't utilize them, HDK motor perches combined with HDK/Schumaker ploy-spool motor mounts for ALL the popular Mopar powerplants are available and interchangeable

sorry for the self-serving promo....but it is a FAQ via privite message and e-mail