All '68-'72 iron 429/460 engines have screw-in studs that must be upgraded to use adjustable roller rockers. The '73-and-later nonadjustable heads (like these fulcrum-style rockers) can be machined to accept adjustable roller rockers.
| Cam Specs |
| | Adv.
Dur. | Duration
@ 0.050 | Lift | LSA |
| Performer-Plus flat-tappet hydraulic |
| Intake | 272 | 194 | 0.460 | 110 |
| Exhaust | 282 | 204 | 0.480 | |
| Performer RPM flat-tappet hydraulic |
| Intake | 290 | 234 | 0.556 | |
| Exhaust | 300 | 244 | 0.581 | 108 |
| Flow Testing |
- Big-block Ford 429/460 aluminum, Edelbrock PN 61649
- 2.19/1.76-inch valves
- 75cc chamber
- 310cc intake port (measured 313 cc)
- Intake-port cross-sectional area: 3.79 square inches
- Exhaust port cross-sectional area: 2.12 square inches
|
Lift
(in) | INT | EXH
(w/pipe) | E/I
(%) |
| 0.100 | 68 | 61 | 90 |
| 0.200 | 136 | 109 | 80 |
| 0.300 | 201 | 148 | 73 |
| 0.400 | 253 | 174 | 69 |
| 0.500 | 300 | 191 | 64 |
| 0.600 | 305 | 202 | 66 |
| 0.700 | 312 | 206 | 66 |
| 0.800 | 320 | - | - |
| The E/I column represents the percentage of exhaust to intake (E/I) flow. Generally, anything around 70 percent or higher is considered good. The exhaust-flow numbers were generated with a flow pipe. |
| Cam Specs |
- Comp Cams Mechanical Roller
- 110-degree lobe separation angle
- Installed at 110 degrees
- Using 1.72 rocker ratio
|
| | Adv.
Dur. | Duration
@ 0.050 | Lift | LSA |
| Intake | 296 | 260 | 0.726 | (minus 0.028) = 0.698 net lift |
| Exhaust | 304 | 268 | 0.726 | (minus 0.030) = 0.696 net lift |
Using the Edelbrock heads and roller rockers also requires slightly shorter hardened pushrods. Grubbs had a set of Pioneer pushrods in stock that are similar to the Cobra Jet units.
| Project 642 |
| This test of The JGM 466ci Ford featured a Comp mechanical-roller cam and fully ported factory iron heads squeezing 12.2:1 compression. Grubbs tested the engine on 110-octane race gas using an Edelbrock Victor 460 single-plane intake and a 1,050-cfm Holley Dominator carb with biggie 2 1/8-inch headers. |
| RPM | TQ | HP |
| 4,000 | 492 | 375 |
| 4,200 | 513 | 410 |
| 4,400 | 539 | 452 |
| 4,600 | 556 | 487 |
| 4,800 | 569 | 520 |
| 5,000 | 565 | 538 |
| 5,200 | 560 | 555 |
| 5,400 | 553 | 569 |
| 5,600 | 551 | 587 |
| 5,800 | 553 | 611 |
| 6,000 | 546 | 623 |
| 6,200 | 541 | 638 |
| 6,400 | 527 | 642 |
| |
| Avg | 543.5 | 539.0 |
| Peak | 569 | 642 |
| Power/ci | 1.22 | 1.38 |