 These 6.000-inch Chevy rods...  These 6.000-inch Chevy rods get 3/8-inch ARP bolts for strength. Side clearances have been checked. Ditto for crankshaft endplay. |  Conventional flat-tappet hydraulics...  Conventional flat-tappet hydraulics are installed for the flat-tappet cam. Notice the painted valley for improved oil return flow. |  Here's a common 351C mistake....  Here's a common 351C mistake. Someone has removed the brass coolant-flow restrictor, which every 351C/351M/400M must have. |
 Here's where a 351C differs...  Here's where a 351C differs from the garden-variety small-block Ford. Coolant never enters the intake manifold because the 351C has a dry manifold. At the upper righthand corner of the 351C head gasket is a coolant passage that carries coolant to the thermostat. The same is true on the other side. Be careful because you can install the 351C head gasket backwards and experience overheating. The little square passages go at the front--and "front" means front. |  This Speed-O-Motive 408C is...  This Speed-O-Motive 408C is getting 351C-4V heads for abundant airflow. On the dyno, it makes 414 hp at 5,500 rpm and 446 lb-ft of torque at 4,500 rpm. The downside is, torque doesn't peak until 4,500 rpm, making even a 408-inch stroker pretty sluggish at low rpm. If you're going racing on Saturday nights, this is a nice package. For cruising, it lacks. Torque begins to come on strong at 3,000 rpm, with a broad torque curve beginning at 3,000 rpm and winding up at 5,500. |  Because the 351C is a wet...  Because the 351C is a wet deck, high-temp sealer is necessary on cylinder-head-bolt threads. Ditto for screw-in rocker-arm studs. |
 Hydraulic lifters are adjusted...  Hydraulic lifters are adjusted the same way as on the 289/302/351W. Set the valve lash at the lobe's base circle (valve closed), tighten the rocker adjustment to snug, then tighten the nut half a turn. These are Comp Cams Pro Magnum roller-tip rocker arms for reduced friction. |  This is the Edelbrock Torker...  This is the Edelbrock Torker 351C, good for high revs with torque coming on strong around 4,000 rpm. For street use and cruising, you need a dual-plane manifold and a Barry Grant Street Demon carburetor. With 408 ci, a 750-cfm carburetor works best. | |
The Aussie Connection: PowerHeads
PowerHeads can set you up with Australian 351C heads that are ported and steel seated for optimum performance. The Aussie Cleveland head has the 351C-4V wedge chamber, coupled with "right-sized" ports for great low and midrange torque resulting in good street performance. The 351C-4V chamber offers good quench, coupled with a tight wedge design for reduced detonation. A little bit of work around the intake valves improve flow. PowerHeads works the ports and bowls, which will help your 351C make more horsepower and torque. You can get into these guys for under $1,000.
Cleveland: The Knudsen Connection
We have long accepted the 351C as a small-block Ford, although its weight and size tend to make it more a middle-block--a small-block with larger heads that makes big-block power. However, the 351C's basic architecture says "small-block Ford" with identical bore spacing and size.
Where the 351C block differs is the wraparound iron timing-set compartment, steel timing cover, and a 12/6-o'clock fuel-pump bolt pattern. At first glance, the front of the 351C/351M/400M block resembles the Oldsmobile Rocket V-8s of the era. All had a wraparound timing compartment with a steel cover and 12/6-o'clock fuel-pump bolt pattern.
Here's a loose theory we wish we could confirm. Did Bunkie Knudsen and the engineering people he brought over from GM spearhead the 351C? Semon E. "Bunkie" Knudsen was hired away from GM's Pontiac Division by Henry Ford II in 1967-1968 to run Ford Motor Company. Key events in Ford history were the result of Bunkie's involvement at Ford: the '69-'70 Boss 302 and 429, '71 Boss 351, '69 Talladega/Spoiler II, bolt-on front fascias, and the pucker-mouth '71 Thunderbird and '72 Torino with the Knudsen "Pontiac" nose.
Did Knudsen influence Ford history underhood? Is his influence the reason there were two 351ci engines? We can envision a huge political struggle between Knudsen's people and Ford's people at the time: Knudsen's people for a revised 351ci engine (ultimately called "Cleveland") and Ford's people in favor of staying with the 351W.
When you study the 351C's architecture with its Oldsmobile-like iron block and big-block Chevrolet-like canted-valve heads with huge ports, could Knudsen's influence have been far behind? What's more, take a good look at the 385-series big-block Fords--the 429 and 460. Note the wide canted-valve heads and block design. Then, study the 396/402/427/454ci big-block Chevrolets. Note the similarities in the two designs. Aside from the front-mounted distributor, the Ford big-block is virtually identical to the big Chevy. Can anyone out there help us solve this mystery?