Small-Block Mopar Stroker Dyno Test - 480hp Mopar Stroker

This is what we started with. Hafliger bought a 360 long-block from a nearby junkyard for a paltry $150. Here it is after being hot-tanked and shot-blasted. "It was really crusty and full of rust, too," Hafliger said. Unlike their RB cousins, LA engines are everywhere, and people are practically giving them away.

This is what we started with. Hafliger bought a 360 long-block from a nearby junkyard for

We've often joked in these pages that the words budget built and Mopar can never be uttered in the same sentence. At least that's what we used to think.

Two months ago, we did a theoretical build of an LA engine using a 318 as the foundation. We cheekily referred to it as an almost-500hp engine you could build for a little more than $5,000. Well, we decided to take up our own challenge and assemble that small-block Mopar. With the help of Brian Hafliger of IMM Engines in Indio, California, we killed our horsepower goal, but we also overshot our budget by a similar percentage. Nevertheless, we still think of this as a good build. Chrysler guys, put this in your Duster and drive it.

Baseline
Start saving money for tires now. This thing is a torque monster. Components: Edelbrock RPM Air-Gap dual-plane; Holley 750 carb with 71 primary jets, 80 secondary jets; TTI 15/8-inch stepped headers; 34 degrees total timing; 155-degree water temperature; 160-degree oil temperature.

Test 1: Best Run
Adding a 1-inch open spacer and jetting up the carburetor produced the best numbers we'd see out of this engine. Components: same as baseline plus a 1-inch open carb spacer and a jet change to 73/84.

Test 2
Next, we tried bigger headers but didn't gain any power. Components: same as Test 1 but substituting larger Hooker Super Competition 13/4-inch headers.

Test 3
We tried even bigger headers, but power was down slightly. Components: same as Test 1 but with TTI 1 7/8-inch headers.

Note: Removing the spacer dropped power substantially-minus 30 lb-ft off peak.

Test 4
We went even bigger with the manifold, and the engine liked it even less. Components: Edlebrock Super Victor intake; Holley 750 carb with 74 primary jets, 83 secondary jets; TTI 1 7/8-inch headers; 1-inch open spacer; 34 degrees total timing; 150-degree water temperature; 165-degree oil temperature.

Test 5
For the last test, we put the smaller headers back on and saw a slight improvement in torque.
Components: same as Test 4 but with TTI 1 5/8 stepped headers.

More power?
Ultimately, the cylinder heads are the cork in this combination. The intake ports have to neck-down substantially to clear the pushrods. This pushrod pinch limits how much air the engine can ingest. You'll have to step up to more expensive heads to get any more power out of this combination, which we may do in a later article.

We did go over our budget, however. We really wanted this thing to come in at less than $5,500 but overshot our goal by nearly a grand. As you see in the pictures, this engine costs $6,973.48 to build carb to pan. "Small-block Mopars are some of the most expensive engines to build," Hafliger told us after we added up the costs.

However, it would be possible to save a few hundred dollars here and there-noncoated headers, reusing the stock rocker hold-down system, and buying a used carburetor, for example. Shop around and you could probably build a similarly potent engine for $6,000. Either way, we were impressed with this combination. Drop this in a light Valiant or Dart and go 11s.