I recently bought a set of #487 iron heads for my 350. I was told that I might have to have screw-in studs and guideplates installed(he said he was quoted about 100 bucks) I called the machine shop and they want 180 bucks plus parts(about $60)to do the job. Do I really need them? I'm building a fairly mild street 355 with Hyp. pistons, a comp cams energizer cam(218dur0.450/.0450lift). The heads have 2.02/1.60 valves and 76cc chambers. I will be using stock 1.5 rockers. The machinist said I should get about 300-320 Hp when it's all said and done. I will not be racing the car. Do I really need to have studs and guideplates installed? Is it possible to do it by yourself if I do need it?