These camshafts are for 1954-'84 big twins with either the Hydraulic Conversion kit or the Cylinder Head Replacement kit for panhead engines. They are also replacement parts for Flathead Power P-Series and SH-Series engines. Since these kits and engines include 1984-'99 style hydraulic lifters, the larger late style roller diameter requires that cams designed for 1984-'99 models must be used to achieve correct valve timing. When choosing a late style cam for this type of engine, be aware that, due to the approximate 1.5:1 rocker ratio of most aftermarket rocker arms for shovelheads, the total valve lift will be reduced by about 9% from the specified value. The specification chart shown here shows specs as used in a pan or shovel engine. These cams are available in generator and alternator styles. Fits: 1954-1965 engines with S&S Head Update kit 1966-1984 engines with Hydraulic Conversion kit P-Series and SH-Series engines Custom generator style engines with 1984-1999 style top end Features and Benefits Quality construction - Made in-house by S&S Cycle in Viola, WI Higher lift and increased valve timing for better performance Quiet, dependable hydraulic valve train when used with S&S Hydraulic Conversion kits View Cam SpecsCam Specifications for 1954-'84 Big Twin Engines Requiring 1984-'99 Style Cams CamApplication Generator Part # Alternator Part #Valve Timing1 Open/Close Valve Duration Valve Lift Lift @ TDC2 Spring Spacing RequiredTappet Type Required Intake Exhaust Intake Exhaust Intake Exhaust 51374"-84" Stock or low compression 106-6028 106-6027 18 degree/38 degree 40 degree/18 degree 236 degree 238 degree .472" .163" .187" No Hydraulic 58574"-80" engines 8.5:1 - 9.5:1 CR 84" - 93" up to 8:1 - 9:1 CR 33-5131 33-5109 20 degree/45 degree 60 degree/20 degree 245 degree 260 degree .540" .172" .166" Yes Hydraulic 60093"-103" engines 9:1 - 10:1 CR 33-5132 33-5058 20 degree/55 degree 60 degree/20 degree 255 degree 260 degree .600" .177" .170" Yes Hydraulic 631High RPM Cam for 93"-103" Engines 11:1 CR 33-5078 33-5080 34 degree/61 degree 66 degree/29 degree 275 degree 275 degree .581" .359" .204" Yes Solid or Hydraulic 64093"-Up Engines 10:1 or Greater Compression 106-4639 33-5108 25 degree/60 degree 65 degree/20 degree 265 degree 265 degree .590" .205" .192" Yes Hydraulic 1Timing designation is function of zero lash @ .053" off base circle. Lifts based on 1.5:1 Rocker Ratio. 2Lifts at TDC are measured at the valve and are for reference only. Overlap valve lifts must be checked on assembled motor. Late Style Cam Recommendations for Shovelhead Engines with Retro Conversion Kit Application RPM Range Compression Ratio If You Used... Then Use... Generator Style Alternator Style 74" - Stock 84" low compression Low - Mid 8.5 and below S&S 450 or Andrews J or A S&S 513 106-6028 106-6027 74" and 80" - Modified Mid - High 8.5 - 9.5 S&S 514 or Andrews #3 or B S&S 585 33-5131 33-5109 84" - 93" Low - Mid 8.0 - 9.0 S&S 514 S&S 585 33-5131 33-5109 93" HC - 103" Mid - High 9.0 - 10.0 S&S 495 or 560S S&S 600 33-5132 33-5058 High Compression High Over 10.0 S&S 495 or 565S S&S 640 106-4639 33-5108 NOTES: In order to achieve stated timing specifications, these cams must be used in engines with 1984-'99 style tappets. These cams should not be ordered as replacement parts for early S&S SH-Series engines, or for any shovelhead engine equipped with stock valve train. For replacement parts for these engines, select stock style cams and tappets. S&S Part #: 33-5058