The next level of small-block offered by Chevrolet Performance is the SP350/385 rated at 385 hp at 5,600 rpm. The Base model (PN 19417624) is built on a four-bolt iron block foundation and features a forged-steel crankshaft, an aggressive hydraulic roller cam, and a beefed-up valvetrain. The big difference comes through the aluminum heads originally based on the proven Fast Burn design. A Deluxe version is also offered with a complete front drive as PN 19417623.
If you’re looking for a high-output crate engine equipped with a reliable EFI system, the classic Ram Jet 350 is still available as PN 19417619. The EFI intake gives a nod to its heritage with a resemblance to the original Rochester mechanical fuel injection system. The EFI is managed by a compact MEFI controller that needs no tuning or programming. The combination delivers a stout 396 ft-lbs with 345 hp.
The top-of-the-line ZZ6 crate engine is the ZZ6 platform, which produces more than 400 hp and torque. This package is the latest in the proven ZZ platform and is available as PN 19417576 for the Base model followed by a Turn-Key, an EFI Deluxe package, and an EFI Turn-Key model. ■
Chevrolet Performance offers a number of crate engines ranging from long-blocks to complete turn-key packages that include a carburetor (or even EFI), front accessory drive, plug wires, and more. This example is the SP350/385 Turn-Key package available as PN 19417623. (Photo Courtesy Chevrolet Performance)
Discontinued and Obsolete Parts
Say you decide that you need a particular part and you check with Chevrolet Performance or even General Motors and find that the part is no longer made. Before your frustration level forces you to contemplate burning your project down, remember that the small-block V-8 was introduced in 1955—some of the parts may be up to 60 years old. As demand lessened for certain pieces, Chevrolet dropped production of those and went on to other designs. If you must have a certain part or casting number, part of the fun will be searching for it.
Before you start, make sure that you know everything you can about the identification of that part, so you know it when you see it. Also, find out what it is worth. Get an idea, before you buy, of the usual price range of the part, new and used. Swap meets, junkyards, and the internet can lead you to the parts you need. However, don’t rely on the description given by the seller. Sometimes the seller doesn’t know what he has or has misidentified the part either intentionally or innocently. Of course, most times the seller knows exactly what he has.
Keep trying. It never ceases to amaze me when I consider what some folks have stashed away in their garages and storage sheds. Be prepared to buy a part you need one week and then to find the same part the following week for one-tenth the price. It happens. I was searching for a particular intake manifold with a particular casting number and casting date to restore a numbers-matching Corvette. I found one in another state and was willing to pay the price, $150, to get it. I was happy to finish the project. Two weeks later, I went to a swap meet. In a pile of intakes, I found the same manifold, with the same casting numbers I needed for $10. One man’s treasure was another man’s junk.
Many parts are still available over the counter from a Chevrolet dealer, so try them first. If you don’t succeed there, try a more specialized dealer or an authorized and licensed aftermarket supplier. Often, these parts are produced using the exact same blueprints and tooling that were originally used to make the parts. Not everything is being reproduced, but with more than 16,000 listed part items, one of them may have what you need. ■
ZZ6 350 HO Crate Motor
The crate motor business is booming, and one of Chevrolet’s most popular crate engines has been the ZZ-series of Gen I small-blocks. The latest version is the ZZ6 which delivers more than 400 hp and torque to match. Think about that, this crate engine delivers more power than any 350 small-block ever installed in a production vehicle! The ZZ6 is available in several iterations:
PN 19417576 is the base model and is supplied with an externally balanced flexplate, aluminum heads and intake, HEI distributor water pump, and damper topped with a set of distinctive center-bolt valve covers. (A short block is also available as PN 12670966.)
PN 19417622 is known as the ZZ6 Turn-Key package and is supplied with the base-model components along with a 770-cfm Holley carb, starter, fuel pump, air-conditioner compressor, power steering pump, alternator, plug wires, and a serpentine belt drive system.
Chevrolet Performance also offers two electronically fuel injected versions of the ZZ6. PN 19368149 is the EFI Deluxe engine that is topped with a port fuel injected intake with a throttle body mounted in place of the carb.
An engine control unit (ECU), harness, and WB02 are supplied to finish the wiring and to get the engine fired up without the need for third-party tuning. A Turn-Key option is also offered for the ZZ6 EFI package, which comes with the accessory drive kit and more. ■
The ZZ6 crate engine from Chevy Performance is the most powerful “production” small-block of all time with 405 hp and 406 ft-lbs. It is offered in a base model, a Turn-Key version, EFI Deluxe, and a Turn-Key EFI package. (Photo Courtesy Chevrolet Performance)
Vortec 5000 and 5700 Engines
In 1996, Chevrolet introduced the Vortec 5000 RPO L30 305-ci and Vortec 5700 RPO L31 350-ci engines and made them available in full-size trucks, Suburbans, and Blazers. These are enhanced Gen I one-piece rear main seal small-blocks, but they feature a number of changes that improve performance. All of these engines have steel hydraulic roller cams and roller lifters, and the blocks have minor lifter-bore changes to use roller lifters along with bolt bosses in the lifter valley to bolt the spiders, which help retain the roller lifters in their respective bores.
The Vortec cast-iron cylinder heads have revised, larger (170-cc volume) intake port runner dimensions and the combustion chambers have been changed to help increase compression. The 64-cc heart-shaped chambers have straight plugs, but the plug bosses move the plugs higher and closer to the chamber roof. The L31 head uses 1.94/1.5-inch valves with pressed-in rocker studs. The intake port openings are 0.080-inch taller than those on previous standard-production Gen I heads. The intake manifold bolt holes in the Vortec heads are positioned at 90 degrees to the head/manifold surface, but the bolt spacing is different and only four bolts are used on each side to mount the two-piece Vortec intake manifold. You must use a revised Vortec intake manifold gasket when using Vortec heads and related production or aftermarket intake manifolds.
Sequential electronic fuel injection with a mass airflow meter is used along with a two-piece intake manifold, which has an aluminum lower base piece and a composite plastic material upper half. Static compression has been increased and the coolant system has been revised to provide better bank-to-bank coolant flow balance. The coolant passages at each end of the heads are larger.
The vibration dampers on Vortec 5000 and 5700 motors incorporate a crankshaft trigger ring for their electronic ignitions and are not interchangeable with other Gen I engines. The Vortec small-block engine blocks also have an additional coolant bypass hole that is not used in other earlier Gen I powerplants.
The 1996 Vortec 5000 305 has increased output to 220 hp at 4,600 rpm and has 285 ft-lbs of torque at 2,800 rpm. The Vortec 5700 has 335 ft-lbs of torque at 2,800 rpm and delivers 250 hp at 4,600 rpm. These engines can still readily be found in donor vehicles and can make a good powerplant for hot rods and pickups, but you need to make sure to use the specific Vortec components from Chevrolet or the aftermarket. ■
You may have heard that a number of race engine builders are using roller cam bearings in their maximum-effort, “take no prisoners” engines.