Competition Cams 54-444-11 XFIXE-R XER273HR-14 Camshaft for LS Gen III/IV, Three-Bolt HYDRAULIC ROLLER - XFIXE-R: High rpm street/strip with XE-R lobe designs. Requires custom tuning. 273/279 Advertised Duration, 224/230 Duration @ .050 inch, .581 inch/.588 inch Lift, 114 Lobe Separation Use Beehive Valve Spring part #26918-16 with this camshaft Improves efficiency Offers a wide power range