'70 Duster Revival: Drag Racing Heart | Pro Touring Soul

As with most engine builds, mine was an ongoing battle of trial and error. Like I said earlier, I wanted to keep the small block 360 but I wanted to get as much as I could out of it naturally aspirated - without sacrificing streetibility. (Disregarding fuel mileage) Luckily I was able to reuse many of the engine parts that came with the car when I bought it. It was a pretty solid motor to start with but it looked and ran rough. (Who spray paints a motor yellow in a red engine bay?) It was an early 80’s 360 already at .040 over bore. A mild Comp Cam, Edelbrock Air Gap and Holley 750 DP helped propel the previous owner to “12’s” in the quarter. (I never did see any of the time slips) Anyway, I wanted more.

Attempt 1

I purchased a couple of early 70’s blocks locally to use for this build. (Thicker castings than the later 360’s) The first block was machined .030. I kept most of the original bolt on’s but added some reworked 340 X heads and a 4” stroker kit. The carb was also rebuilt. The dyno results were a little disheartening. (About 370 HP / 400 ft./lb. TQ) Jamey my engine builder said that his dyno was a little conservative and could be off by about 5% but I still wasn’t satisfied. The heads and cam were the biggest drawbacks. Not enough flow, lift or duration for the new stroker setup. While on the dyno we also noticed there was a little water in the lifter valley. Jamey my builder was the first to notice and he didn’t want to take a chance… so we were back to square 1 and block #2.

Attempt 2

Block #2 was bored .040 over. I ditched the X heads in favor of the Edelbrock Performer RPM’s and swapped the little solid mechanical cam for a larger custom ground Comp Cam hydraulic roller. Everything bolted up together nicely aside from a little work needing to be done to get the pushrods at the right angle. The Holley was re-jetted to match the new changes. While everything was being redone the piston rings were also gapped for nitrous. The second time around the combo was good for a healthy 505 HP / 553 ft./lb. TQ. I was much happier, especially since I knew I could still safely add a 150-200 shot of nitrous down the road.

Parts listing to come in the next post.