6331 - Full Mod / Signature Series Twin Top Ends 57CC & 61CC

Replacement full mod or signature series twin top end set. These top ends have been machined for twin use and our billet heat sink. Full mod is our production CNC porting and will have good power from torque through top rpm's. The signature series are ported more aggressively and will have quite a bit more power than the full mod version. We also offer custom tuning on any signature series top ends/engines upon request at no additional charge. If ordering signature series porting please email us if you would like custom tuning.