Butler Exclusive Pontiac McKellar #10 Super Duty Hydraulic Roller Retrofit Camshaft, 236/245 @.050, .428/.470 HR113

New Butler exclusive "Super Duty" SD Series RetroFit cam. The McKellar #10 was Malcolm "Mac" McKellar's hottest street-legal Super Duty grind — GM part #541596, 308°/320° advertised duration and .447"/.446" lift on 1.65 rockers, the camshaft that ran in the 1963 421 Super Duty Catalinas. We had COMP CAMS reproduce that profile's character as a hydraulic roller.

You get the long-duration McKellar powerband and the sound that goes with it, but on a roller lobe — no flat tappet break-in, no lobe wipe risk, no ZDDP anxiety, and modern ramp rates that are far easier on the valvetrain. Lift comes out slightly ahead of the original: .470" on 1.65 ratio rockers, versus the .447" the factory grind made.

Made in the USA and custom ground right here in Tennessee.

Specifications
Duration @ .050": 236/245
Lift with 1.5 ratio rockers: .428
Lift with 1.65 ratio rockers: .470
Lobe Separation Angle: 113
Hydraulic Roller, Retrofit, Standard Firing Order / Standard Journals

Application
This is a serious street and strip grind, not a mild upgrade. The long seat timing wants compression and a converter to work with it — plan on a healthy static compression ratio and a stall converter if you're running an automatic. In the right combination it pulls hard through the midrange and up top with the aggressive idle Super Duty cars were known for.

BP/Comp Recommended Cam Degree
For 110 Lobe Sep.- Install Int. Lobe CL to 106
For 112 Lobe Sep.- Install Int. Lobe CL to 108
For 113 Lobe Sep.- Install Int. Lobe CL to 109
For 114 Lobe Sep.- Install Int. Lobe CL to 110

Valvetrain
Because peak lift stays at .470" even on 1.65 rockers, this cam works with our standard hydraulic roller spring packages — no oversized spring or extra machining required for coil bind clearance. For stock cast iron D-port and HO round port heads, see CCA-995-16 or the complete kit BPI-SK-HR-995. For Edelbrock, RA-IV, or SD heads, see EDL-5845, BPI-SK-HR-5845, or DHP-S-084-283-16.

Requires hydraulic roller lifters. **Stock valley pan will not allow clearance for tie bar on hyd roller lifters. See TPP-041 or BFA fabricated valley pans.**