I would go with no more than an 8" drop. Actually the 6" would be my preference. Its very doubtful that you loaded MH will drop more than an inch or so...You never see a MH low in the back because of load do you???
Remember the drop will drag on driveways badly....the long the drop the more problem you will have. The leverage effect on the drop will be exaggerated more with the longer drop bar. The real danger of unequal hookups from level is when the MH hitch is lower than the toad. A remote chance of a sudden stop or impact will force the toad forward and up. Very doubtful that the reverse would happen. The toad going under the MH.
