Chevy Craft, Camaro Craft, Chevelle Craft, yes, we here at CC have been accused of that from time to time. Some might even say all the time, though our archives prove otherwise. However, we do admit to not being as well versed on other manufacturers' offerings as we are with the stuff from Chevrolet. Case in point is the small-block Chrysler, known as the LA engine. We all know you can make really big power with a 440 or 426 Hemi, but we weren't fully aware of the power potential lurking within the thin wall castings of the LA, a lightweight evolution of the earlier A engine, hence the L prefix.
The LA went into production in 1964 as a replacement for the A engines. The main difference between the two is the cylinder head configuration. The A engines had polyspherical combustion chambers with the intake valve canted toward the intake manifold. Unlike the Hemi heads, the poly heads used a single shaft per head to mount the rocker arms, likely done as a cost-cutting measure. Hemi engines used separate shafts for the intake and exhaust rocker arms.
Our LA tour of power (not...
Our LA tour of power (not to rip off sister magazine Hot Rod) began with a trip to JMS Racing Engines in El Monte, California. Owner Mike Johnson patiently gave us the lowdown on these engines and was the first to tip us off to the stroker being the hot-ticket build. In fact, he's packaged up a stroker combination for LA engines to sell on eBay. The kit includes either a Scat or Eagle crank, H-beam rods, and forged pistons, plus all the required rings and bearings. Johnson said the majority of kits he sells are for 318s, which we found odd until he told us that, in a 318 block, this combination adds up to 390 ci. He sells these things all day long for $1,495, and Johnson says owners can expect 75 to 85 lb-ft more torque with the extra stroke.
The LA engine was designed with wedge-shaped combustion chambers, and the intake and exhaust valves were arranged in a row. The simpler valvetrain design allowed for a more compact cylinder head that gave Dodge and Plymouth engineers the clearance they needed to drop a V-8 into the narrow confines of the Valiant and Dart engine compartment. As an added bonus, the thin wall castings of the engine block added up to a 50-pound weight savings over the A engine-you could have the performance advantage of V-8 power in a small car without the weight penalty of a heavier casting.
The first LA engine was the 273, which made its debut in 1964. It was followed closely by the 318 in 1967, the 340 in 1968, and the 360 in 1971. Of all these configurations, the 318 and 360 engines survived the longest, soldiering on until 2002. Note that the A engine family was being phased out during the time that the LA engines were rolling out, so it's possible to see a poly 318 in 1967 alongside an LA 318. Throughout their run, the LA 318 and 360 engines saw several updates, notably the introduction of throttle-body fuel injection and roller cams in the '80s, culminating with the Magnum versions in 1992 and 1993, respectively. The LA V-8s were phased out by 2003, being replaced by the 4.7 V-8s in the Jeep Grand Cherokee and the new Hemi engines.
This is an LA cylinder head....
This is an LA cylinder head. Though the shaft-mount rocker arm system is carried over from the A engine, note that the valves are all lined up in a row.
Still, a 30-plus-year production run means small-block Chrysler engines are readily available for building. Though largely overshadowed by their big brothers, the B and RB engines (383, 440), there is plenty of performance potential in the LA. We talked with several experts to get their build ideas, and the overwhelming consensus was to build a stroker. It turns out you can put a 4-inch-stroke crankshaft into any LA block without clearancing and really pump up the cubic inches. Of course, more cubic inches mean more power, right? Interested? Read on...
LA Engines By the Numbers
Years in production: 1964 to 2003
Bore spacing: 4.46 inches
Deck height: 9.60 inches
| Displacement |
Bore |
Stroke |
| 273 (4.5L) |
3.625 |
3.31 |
| 318 (5.2L) |
3.91 |
3.31 |
| 340 (5.6L) |
4.04 |
3.31 |
| 360 (5.9L) |
4.00 |
3.58 |
Firing order: 1-8-4-3-6-7-5-2
No. 1 cylinder on driver side front/distributor turns clockwise.
Random factoid: Did you know the 3.9L V-6 and 8.0L V-10 are also based on the LA architecture?