The Crane R290-446-04 is the oldest cam, an early SS Cam, 290 @.050 int and exh, .446 lobes int and exh, LSA 104, 82 overlap, gross Int lift .700, Exh .678. This was generally replaced by the R292-500-06, .500 lobes, LSA 106, 80 overlap, gross lift .785/.760. The SS/DA cam was the R286-500-04,.500 lobes, LSA 104, 78 overlap, gross lift .785/.760. The R296-4778-08 was known as a 4 speed SS/A cam, .478 lobes, LSA 108, 80 overlap, gross lift .750/726.