I recently changed to a roller and larger cam. My first cam was a:

Camshaft Specification Table
Part Number 12-212-2
Engine 1955-1998 Chevrolet
262ci-400ci
8cyl.
Grind Number CS 280H-10
Description

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Intake Exhaust
Valve Adjustment 0 0
Gross Valve Lift 0.48 0.48
Duration At 0.006 Tappet Lift 280 280

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Valve Timing At 0.006
Open Close
Intake 34 66
Exhaust 74 26

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These Specs Are For The Cam Installed At 106 Intake CL
Intake Exhaust
Duration At 0.05 230 230
Lobe Lift 0.32 0.32
Lobe Separation 110

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Recommended Valve Springs 981-16



Second and roller cam was as fallows


Camshaft Specification Card BACK TO LIST
Part Number: 119661 Grind Number: HR-230/359-2S-12.90 IG
Engine Identification:
Start Yr. End Yr. Make Cyl Description
1957 1987 CHEVROLET 8 FAIR IDLE, PERFORMANCE USAGE, GOOD MID-RANGE TORQUE AND HP, 3600-4400 CRUISE RPM, 10.0 TO 11.5 COMPRESSION RATIO ADVISED, .900" BASE CIRCLE FOR LONG STROKE CLEARANCE. BASIC RPM 3000-6500
Engine Size Configuration
262-400 C.I. V

Valve Setting: Intake .000 Exhaust .000 HOT

Lift: Intake @Cam 359 @Valve 539 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 372 @Valve 558
Rocker Arm Ratio 1.50

Cam Timing: TAPPET @.004
Lift: Opens Closes ADV Duration
Intake 35.0 BTDC 77.0 ABDC 292 °
Exhaust 83.0 BBDC 37.0 ATDC 300 °

Spring Requirements: Triple Dual Outer Inner
Part Number 99838
Loads Closed 112 LBS @ 1.650 or 1 21/32
Open 327 LBS @ 1.120
Recommended RPM range with matching components
Minimum RPM 2600
Maximum RPM 6600
Valve Float 7000

Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 8.0 BTDC 42.0 ABDC 107 230 °
Exhaust 56.0 BBDC 2.0 ATDC 117 238 °

Remarks:


The blue run was with my old cam, the red with the roller. I lost over 40hp on this cam change. Any thoughts on why. The car runs good, I have put over 5000 miles on the roller. I did notice a large loss in throttle response and gas mileage went from 19mpg to 15mpg.

Any ideas will be appreaciated

Dennis