valves. The TT employs inconel, a high nickel content superalloy which is quite resistant to heat. The NA engine uses stainless steel which does not have as high of a thermal resistance, however, EGT's on a higher compression engine are going to be lower so it may just all trade off. The rods and crank are identical to the TT so I dont see that being any more prone to failure on a SC'd or turbo'd NA engine.