Hey guys I have a 88 5.0 and picked up a set of gt40 heads that I am porting and am looking at buying a set of harland sharp roller rockers used but they are 3.8 stud mount with guide plates. What is need to make these work? do the pedastals need to me milled? and are the bolts 7/16 or 3/8? if they need to me milled what should I expect to pay at a machine shop to do the work thanks