Designed for high rpm, BC valve springs by PAC Racing are wound from only the highest grade, super clean, chrome silicone alloy and feature proprietary processing procedures for consistent pressures. BC retainers are machined from premium 6AL4V titanium alloy for added valve control above 10,000 rpm. Also includes BC3991 integrated valve seat/seal.
NOTE: Does not work with over .430" lift camshafts. Retainer to seal contact will cause extensive damage to the head.
| Type | BC1900 Single |
| Free Length | 1.610" |
| Seat | 1.265" @ 83 lbs |
| Open | 0.850" @ 197 lbs |
| Coil Bind | 0.760" |
| Retainer | BC2901S |
| Valve Seal | BC3991 |
| Net Cam Lift | 0.430" w/BC3991 Seal |