Lykins and I have had this fight a thousand times. He can generally argue the facts pretty well that the right hydraulic cam will do everything, including rev, as well or better than a solid flat tappet. He doesn't like solid rollers either. I don't believe he's ever addressed the "sound" issue, but I have heard some of the newer thumper cams that did sound nice -- but they don't have the tell-tale sewing machine, clackity clack noise of a SFT. On the other hand, I did have a tried & true car guy ask me "is your engine supposed to sound like that?" So I guess it cuts both ways. If you go with the roller, solicit thoughts on just pressing an iron gear on the end of it. Personally, I wouldn't go with a solid roller in an FE. You can get as much horsepower as you want with a plain old SFT. Once it's broken in, it'll pretty much last forever if you just remember to use the right
oil.