can anyone tell me on a 68 coronet rt , how high the front should be from the ground and where I should measure from ?

It's the difference of two measurements under the suspension. You can down load a service manual for free on mymopar.com. Maybe somebody could post the pictures of where to measure.

There's pictures in the service manual.

You can set the ride height where you want it (so the front wheels/tires look "good" in the wheelwells) within reason especially needed with aftermarket rims/tires. As you know loosen the front nuts on the (2) tapered studs before cranking the bolts & bounce/jounce the front end to let it settle for a final check to get the height where you want it. Alot of shops set the RH too low going by their "book" specs.

ok thanks for the help