Cheapest bolt-on for a 351C 2V — the 4bbl intake and carb swap
Engine dyno, as configured — flywheel horsepower. Standard test config: stock manifolds through 18" of pipe, air cleaner lid flipped, no accessories driven. Factory SAE net ratings are measured as‑installed and read 15–25% lower. Rev ceiling for this combination: 5000 rpm.
Where each one wins
| RPM | stock 2bbl | 4bbl intake + 600 | diff |
|---|---|---|---|
| 2000 | 267 | 281 | +14 |
| 2500 | 269 | 300 | +31 |
| 3000 | 270 | 313 | +44 |
| 3500 | 274 | 324 | +49 |
| 4000 | 255 | 308 | +53 |
| 4500 | 235 | 287 | +53 |
| 5000 | 213 | 256 | +43 |
Torque, lb-ft, at the flywheel. Everything except the part named is identical between the two runs.
The most common first move on a 2V Cleveland: an Edelbrock Performer 2750 — a four-barrel manifold that fits 2V ports — and a small four-barrel on top. Nothing else touched.
It is a real gain and a modest one. Anybody promising you fifty horsepower from an intake and a carburettor on an otherwise stock engine is selling something.
Note the part number. The 2750 is the 2V-port casting; a 4V intake will not seal to a 2V head, which is a mistake that gets made often enough that the tool refuses to let you do it.
The build
| Block | Factory 351C 2-bolt main (stock) |
|---|---|
| Crank | Stock cast iron — 3.50" stroke (351 ci) |
| Rods | Stock I-beam (factory) — to ~450 HP |
| Pistons | Generic OEM-style dish (−7cc) |
| Head gasket | OEM compressed (.040") — neutral |
| Cylinder heads | 2V US open chamber (75cc) — the common head |
| Porting | As-cast / stock |
| Camshaft | Stock 2V — hyd flat tappet (D0AZ-6250-B, .400" lift) |
| Valve springs | Stock 2V springs |
| Rocker arms | Stock stamped 1.73 rockers |
| Intake manifold | Stock 2V cast iron — factory 2bbl flange |
| Carburetor | Autolite 2100 2bbl — stock 351C-2V · 1.21" venturi · 351 cfm @3.0" (≈250 4bbl-equiv) |
| Exhaust | Stock manifolds + 18" pipe — DYNO STANDARD |
| Ignition | Stock breaker points — floats ~5,200 rpm |
| Fuel | Pump 87 octane |
| Air cleaner | Stock air cleaner, LID FLIPPED — DYNO STANDARD |
The other one
| Block | Factory 351C 2-bolt main (stock) |
|---|---|
| Crank | Stock cast iron — 3.50" stroke (351 ci) |
| Rods | Stock I-beam (factory) — to ~450 HP |
| Pistons | Generic OEM-style dish (−7cc) |
| Head gasket | OEM compressed (.040") — neutral |
| Cylinder heads | 2V US open chamber (75cc) — the common head |
| Porting | As-cast / stock |
| Camshaft | Stock 2V — hyd flat tappet (D0AZ-6250-B, .400" lift) |
| Valve springs | Stock 2V springs |
| Rocker arms | Stock stamped 1.73 rockers |
| Intake manifold | Edelbrock Performer 351-2V #2750 — 4bbl flange, 2V ports |
| Carburetor | Holley 600 cfm 4150 |
| Exhaust | Stock manifolds + 18" pipe — DYNO STANDARD |
| Ignition | Stock breaker points — floats ~5,200 rpm |
| Fuel | Pump 87 octane |
| Air cleaner | Stock air cleaner, LID FLIPPED — DYNO STANDARD |