Re: 390 Combination
Part Number: 343801 Grind Number: H-278-2 (REPLACES HMV-278-2)
Start Yr. End Yr. Make Cyl Description
1963 1976 FORD-MERCURY 8 GOOD IDLE, DAILY PERFORMANCE USAGE, MILD BRACKET RACING, 3000-3400 CRUISE RPM, 9.5-10.75 COMPRESSION RATIO ADVISED. BASIC RPM 2200-5200
Engine Size Configuration
352-428 C.I. V
Valve Setting: Intake .000 Exhaust .000 HOT
Lift: Intake @Cam 3114 @Valve 548 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 3294 @Valve 580
Rocker Arm Ratio 1.76
Cam Timing: TAPPET @.004
Lift: Opens Closes ADV Duration
Intake 26 BTDC 72 ABDC 278 °
Exhaust 80 BBDC 30 ATDC 290 °
Spring Requirements: Triple Dual Outer Inner
Part Number 99837
Loads Closed 90 LBS @ 1.828 or 1 53/64
Open 283 LBS @ 1.268
Recommended RPM range with matching components
Minimum RPM 2200
Maximum RPM 5200
Valve Float 6500
Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 2 BTDC 40 ABDC 109 222 °
Exhaust 56 BBDC (2) BTDC 119 234 °
Although I don't know how it would effect the performance, I don't like the offset lifts. The high lift exhaust must be for restrictive systems.
Can't see the intake being restrictive because the RPM is the best FE intake available.
I have a B&M 2600 stall with 4.10s in the back. I think my exhaust maybe a little restrictive considering its 2-1/4" with 2-90 degree pinched bends. My plan is to replace it with 3" straight pipe dumped like 5 feet out with an H-pipe. No dyno runs. The hp calculator online estimates like 280hp at the wheels, taking the altitude/track time/trap speed, which I find greatly disappointing. The 'Desktop Dyno' is apparently within 5% accuracy, and it says 420hp at the flywheel.