The Ford Racing hydraulic roller camshaft for small-block V8s (.480 in. lift) is a performance cam that is intended to work only with mass-air-induction EFI systems. It requires upgraded valve springs capable of high seat and open pressures (minimum seat pressure ~120 lb and ~295 lb open), so use of appropriate springs and installation hardware is necessary for reliable operation.
Ford Racing Small Block V-8 Hydraulic Roller Tappet Camshafts