NCRick said:To reap the full benefit from the kit, you should unshroud your valves so that the heads can take advantage of the extra area and flow better.i've heard about this several times but still don't understand what it means. i know what it does. is it "kind of like" boring the head, that widens the area on the bottom of the head to match the new cyclinders. If so can i do it, i mean take it to a shop that machines stuff for cars, or does the Nakasyl (or however you spell it) need replating?
on the subject, what kind of numbers are returned by unshrouding. I gather an 851-3 kicks the 748 to about 104hp. Is that with unshrouding or w/out? Unshrouding +/- 2 hp or so?
on the subject and you knowing about the engines, what can be expected, on a 748, for 32mm intake and 30mm exhaust valves? and at what size valves does, if not always, does the engine have to running harder (higher) to get at the gains from valve size increase?
lastly for those of us like me, who opt for the thrifty route, how much you expect a 748 bore and plating costs? and for plating, is that something easily done or do i need to find the best shop in town to do it?