SOLD Butler Crate Engine 400/467cu in., 620+hp 600+ Tq, EFI Engine

629 horsepower and 610 lb-ft — pump gas, naturally aspirated

A Butler Performance build on a Pontiac 400 block: four-bolt converted with billet main caps, bronze-bushed lifter bores, CNC-ported 340 CFM round port heads and a Northwind intake port matched to them. Assembled and blueprinted in our own shop, dyno tested and tuned before it shipped.

Bronze lifter bore bushings — the part almost nobody does

This block had its lifter bores machined and bushed with bronze BHJ bushings — the block machined for them, oil holes drilled, then each bushing installed and honed to fit. Sixteen of them.

Here is why it matters. A production Pontiac lifter bore is cast iron, cut once at the factory, and a high-lift roller cam puts far more side load into it than the engine was ever designed for. Worn lifter bores bleed oil pressure, let the lifter rock, and take the cam and lifters with them when they finally give up. Bushing them restores a true, round, correctly sized bore in a harder material with the oil feed put exactly where it should be.

It is invisible on a spec sheet, it costs real money in machine time, and it is one of the clearest signals of how an engine was built rather than assembled.

340 CFM round port — the top of the range

The heads are Butler 87cc Edelbrock round port castings CNC ported to 340+ CFM, supplied complete. That is the highest-flowing head package we build short of wide port, and it is what puts the top end in this engine.

Flow that high is only worth paying for if the induction keeps up, so this one runs the Butler Northwind 4150 intake with water crossover, port matched to the 340 CFM head, with a billet fuel/airflow equaliser beneath the throttle body. Head, intake and injection sized to each other — that is where the power comes from, not from any one part in isolation.

Self-tuning EFI

Fuel is Holley Sniper 2 self-tuning EFI with the handheld monitor in black finish. Spark is a Holley EFI Pontiac dual-sync billet distributor with a HyperSpark coil and an MSD 6EFI digital box with built-in rev limiter, so timing is under EFI control rather than fighting it.

Self-tuning means it adapts as it runs — you are not locked to a tune written for someone else's engine, and it was dyno tuned here before it left.

Built to be leaned on

The short block is a Butler 400 kit: forged crank, ARP2000 rod bolts, four-bolt mains with billet caps, align bored across three caps and sonic tested. Valvetrain is Comp cartridge hydraulic roller lifters, Butler 1.65 Tru-Ratio Endurance rockers and oil-restricted two-piece Smith Bros pushrods.

Oiling is a Butler PRO 80 psi pump with a hardened drive shaft feeding a Canton 8" 7-8 quart pan, and the crankcase runs a GZ Motorsports billet hi-flow vacuum control valve into billet valve covers with an integrated evac bung and baffle.

Why the curve matters more than the peak

Peak horsepower is one instant. What moves a car is the area under the curve, and this one is broad at both ends. Torque is over 590 lb-ft from 4,100 to 5,300 and still above 500 at 6,500. Horsepower is still climbing at the end of the pull — it makes 629 at 6300 and has not signed off by 6,500.

That combination — a fat mid-range that carries all the way to a top end that keeps pulling — is what the 340 CFM heads and the matched Northwind intake are for.

Specification — as built

The pull — corrected

Built the Butler way

Butler has been building Pontiac engines since 1974. Every engine that leaves here is assembled and blueprinted in our own shop and run on our own dyno before it ships — we don't ship an engine we haven't heard run. The dyno sheet goes with it.

Want this combination in a different displacement, on a carburettor instead of EFI, or built to a particular power target? Talk to our tech department — that is what we do all day.