[Si Coe]

The droop screws on the front wishbones work against two small tabs that stick out of the bulkhead. The tresrey bulkhead lacks those two tabs, so the droop screws have nothing to push against.

Whether or not you need the whole shim set depends on how many shims (if any) you have under ballstuds. The 'full set' is enough for all the most setups.