393 Cleveland with Aussie 2V heads and an Air-Gap
within 1% of peak across that whole range
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: 6000 rpm.
Everybody puts big heads on a stroker. This is the opposite: 393 cubic inches breathing through closed-chamber Australian 2V heads.
The logic is port velocity. More displacement asking for air through a smaller port keeps the speed up, and speed down low is what makes an engine feel strong on the street. It will not win a horsepower contest and it is not trying to.
If you have a set of Aussie heads sitting on the shelf and you were about to sell them to fund 4Vs, run this build first.
The build
| Block | Factory 351C 2-bolt main (stock) |
|---|---|
| Crank | Eagle forged 4340 — 3.85" stroke / 393 ci (~$800) |
| Rods | H-beam 4340 forged (Eagle/Scat/Molnar) — builders' guide ~900 HP |
| Pistons | Auto Tec 1000524 forged 4032 dish 4V — 393 · 1.260" CH · −11.7cc · ~$799 |
| Head gasket | OEM compressed (.040") — neutral |
| Cylinder heads | 2V Aussie closed chamber (58cc) — quench, the 2V to have |
| Porting | As-cast / stock |
| Camshaft | COMP XE274H — hyd flat (32-246-4 · 230/236 @.050 · .562"/.565") — Holdener +44 HP vs Boss cam |
| Valve springs | COMP 916-16 dual |
| Rocker arms | Full roller 1.73 — needle bearing |
| Intake manifold | Edelbrock Performer 351-2V #2750 — 4bbl flange, 2V ports |
| Carburetor | Holley 650 cfm 4150 |
| Exhaust | Long tube 1-3/4" — hot street |
| Ignition | MSD Pro Billet distributor + 6AL box — ~8,000 rpm |
| Fuel | Pump 91 octane |
| Air cleaner | Stock air cleaner, LID FLIPPED — DYNO STANDARD |
These numbers assume a proper dyno tune — timing and jetting set on a dyno, not guessed at in a driveway. It is worth 15 hp on this combination, and it is the one line on this page you cannot buy: we build the parts list, you pick the tuner. Leave it untuned and the engine will run, it just will not read what it says up top.
Change these numbers yourself