🔧 Pontiac 400 HO V8 Engine
Pontiac's 400 cubic inch (6.6L) High Output V8 was the performance engine of choice for the GTO, Firebird, and Bonneville from 1967 through 1972. Its "round port" heads on the Ram Air versions flow 330+ cfm per port — comparable to purpose-built race engines. The same block, crankshaft, and connecting rods serve the GTO 1964/1968 (using the 389/400), the GTO Judge, and the Trans Am. At 366 hp on Ram Air III and 370 hp on Ram Air IV, Pontiac's 400 was the most powerful naturally-aspirated American engine of its displacement in 1969.
Engine
Technical Specifications
| Type | Naturally Aspirated OHV V8 (W-series block) |
|---|---|
| Displacement | 6,554 cc (400 cu in) |
| Bore | 104.6 mm |
| Stroke | 95.25 mm |
| Horsepower | 335–370 hp (Ram Air III/IV) |
| Torque | 576–610 Nm |
| Carburettors | Rochester Quadrajet 750 CFM or Holley 800 CFM |
| Valvetrain | OHV pushrod, 2 valves per cylinder |
| Block | Cast iron |
| Manufacturer | Pontiac Motor Division, Pontiac MI, USA |
| Msrp | $2,800–$8,000 (rebuilt) |