Rollmaster Romac Steel/Alloy Blower Harmonic Balancer Suit SB Chev 262-400, Internal Balance With Dual Key, 6 Bolt with .002" Under I.D (RO0202SA/B-6-002)SB CHEV 350 400 6. 2" INT. BAL. Suit SB Chev 262 400, Internal Balance With Dual Key, 6 Bolt with . 002" Under I. D Part Number: RO0202SA B 6 002 Blown or Supercharged Balancers 4340 grade Steel Inner Hub Alloy Outer Ring, for Street, Strip or Marine applications with dual keyways. STD 3 16" and 1 4" 180 degrees opposite. Larger seal area with special seal included in the package. Available in External or Neutral Balance configurations. Weight saving