World Products 427ci Small Block Chevy

"It's a great street engine," says Mitchell. "It idles great and makes lots of power down low; you can cruise all night with this."

Much of the street friendliness of the big-carb motor is due to a special-grind camshaft from Crane that produces great idle quality and very good high-rpm power. Not surprisingly, Mitchell wouldn't divulge the cam's specs, but our experience with his crate engines has shown that they seem to strike a great balance of power and tractability.

World Products rounds out their engine assemblies with an HEI-style distributor, plugs, wires, deep sump oil pan, and SFI balancer and a great looking set of valve covers. As with most other crate engine packages, vehicle-specific items, like the water pump and headers, are left to buyer to source.

Each engine, however, is dyno tested before being crated and shipped.

So, what'll it do?

What is the all-aluminum 427-cid Motown small-block worth on the dyno? At our writing, Mitchell was still trying to determine an average on which to base his advertised claims, but here's what he told us:

"They've been making around 535 hp and 540 lb-ft of torque," he says. "They run right up to 6,300 rpm, too."

Mitchell says he's surprised because the aluminum engine is making as much and, in some instances, more power than comparable iron-block engines. "It's puzzling," he says. "Power should have probably dropped a little, due to the thermal differences between the iron and aluminum, but we got just the opposite. It was a pleasing surprise, to say the least."

Mitchell attributes the engine's stalwart performance to the extra-rigid aluminum block and its numerous strengthening features, which probably provide less flex in the reciprocating assembly. Regardless, the lightweight small-block makes power--tons of it.

If you're thinking all this performance wrapped in a lightweight package must come at price, you're right. The all-aluminum Motown is not an inexpensive option. It adds approximately $2,000 to the bottom line of the base price of a Motown crate engine, and the iron-block versions of the 427 start at around $8,995.

So, you're looking at package of about $11,000 to $12,000 when they've nailed the crate shut and maneuvered the forklift into position.

But, compared to some exotic race castings, World's aluminum block costs roughly half and were designed as much for street performance as competition.

"We learned a lot in the manufacture of other parts that really helped make this affordable," says Mitchell. "We wouldn't have done it if we were building just 100, or so, each year for sprint cars."

There's an undeniable "wow" factor, too, that plays an important role. You wouldn't want to paint this block - just let the aluminum color and external ribbing do the talking under the hood of a Pro-Touring '69 Camaro"I think it'll look awesome polished," says Mitchell.

Indeed, others have thought so, too. Since making the all-aluminum Motown engine available, it has quickly become one of the company's best sellers.

It's hard to argue with the benefits of lower weight. Your doctor will tell you that, and so will Bill Mitchell.