9" drum hub drill to BBP?

Yes it can be done as there is enough meat to do it for the front. I agree about not wanting to do so as there are many better options out there. ''IF'' you do it yourself, what I did was get the 4 to 4 1/2 adapter to use as a templet. I found some at a swap meet for a $1 each.Remove the studs from the 4 1/2 and bolt the adapter to the hub.Drill and tap the hole for the 1/2'' screw in studs from the aftermarket such as Moroso.