Part Number: 688801 Grind Number: R-260/420-2S-8
Engine Identification:
Start Yr. End Yr. Make Cyl Description
1970 1978 PLYMOUTH-DODGE-CHRYSLER 8 Good mid range and upper RPM torque and HP, rough idle, performance usage, oval track, bracket racing, auto trans w/3500+ converter, 11.5 to 13.0 compression ratio advised.
Engine Size Configuration
383-440 C.I. V
Valve Setting: Intake - .020 Exhaust - .020 Hot/Cold - HOT
Lift: Intake @Cam 420 @Valve 630 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 420 @Valve 630
Rocker Arm Ratio 1.50
Cam Timing: TAPPET @ .0205
Lift: Opens Closes ADV Duration
Intake 41.0 BTDC 71.0 ABDC 292.0 °
Exhaust 81.0 BBDC 39.0 ATDC 300.0 °
Spring Requirements:
Part Number 99896
Loads Closed 150 LBS @ 1.900 or 1 29/32
Open 460 LBS @ 1.300
Recommended RPM range with matching components
Minimum RPM 3800
Maximum RPM 7600
Valve Float 8200
Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 26.0 BTDC 54.0 ABDC 103 260.0
Exhaust 66.0 BBDC 22.0 ATDC 113 268.0
Remarks: