Chevrolet SB 262-400 1955-1998 Big Bottle Cams - 4/7 Swap Adv. Duration: 299/311 Duration @ .050": 267/279 Lift: .645/.640 Lobe Separation: 112 Included Lifters: No 4000-8000. Small Base Circle, Competition, 383+ ci. Mid to upper end power. Multi-stage system.