How so? Pedestals aren't adjusted at all, so I'd say peds are easier to adjust
There is a kicker with pedistal rockers though. . . you need to check the roller travel on the valve stem and lifter preload. If they are off, you need to change your pushrods; whereas, with adjustastable (studmount) rockers, you can set that yourself.
In either case you will just use whatever your heads are machined for unless you want to pay some cash to get them threaded and milled for studs.
honestly i would just use peds for e-7's.....or gt 40's for that matter. For adjustment they sell shims so you can do all the adjustment range that you could with stud mounts, it just takes longer......they have always worked fine for me