340 heads

you dont need to mill the pedestals off the use roller rockers...they milled the pedestals off to raise and move the rockers for taller installed height and larger springs/retainers..

also probably to correct rocker sweep...

you kind of need to find what stands they were milled for.....Do you need offsetted stands(w2/w5) or stands the put the shaft on center but higher?

and same thing with shafts....do you need shafts that are off center or on center?