1) What did the GTI-R prototype camshaft tested in Shaggy's car end up being designated? C1, C2, or C3? Or was it never finished?

2) If I install the heavy duty valve springs designed for the C series cams, but I decide to go back to the S3/S4 cams, will the valvespring harmonics be wrong for the S series?

2) If I install the heavy duty valve springs designed for the C series cams, but I decide to go back to the S3/S4 cams, will the valvespring harmonics be wrong for the S series?

They actually gained 2-3 hp (at high rpm) with the JWT valvesprings on the S3 cams because of better harmonic control.