I know that the older slant truck motors had a shot-peened forged crank. What about the cast cranks in the newer motors, is the truck crank still stronger than the passenger car crank? Or no difference at all? What about the difference in cams? Do the truck cams have a higher lift? I am running a 84 truck motor in my 74 Duster, with a super six set up, a rebuilt Holley carb from a 318 motor, 2 1/4 exhaust and a 2.76 rear. Is there a way to gain more performance out of this setup without changing the rear end ratio or valves? It feels like my 73 dart with a one barrel has more power.

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How many miles does the '84 motor have. Pulling around that heavy truck can really work a slant over good after 20 years. Have you done a compression test? I don't recall seeing of differences in the crank used in cars vers trucks after they went to the cast crank, but I'm no expert as you know.

I expect from seeing your collection that you've given the duster a good tune-up by now. Timing, cap, rotor, wires, air filter. Check the Heat riser operation.

If you're comparing a super six motor with 2.76 gears to a 1bbl motor with 3.23 gears, I think the super will still feel like a slug at a stoplight.

You could have the head shaved to increase compression and get a look at the condition of the valves/ bores while you're in there.

The newer motor has a hydrolic cam. You could have a problem with the lifters or cam. I don't know what to tell you on that. The '84 cam specs ARE different from the '74 motor. The anti pollution cam grind might be a performance killer?

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1980 Aspen 225 super six

The 84 motor has about 79,000 miles on it. I rebuilt the head, replaced the pan and pickup tube and checked compression. I think it could still be a timing issue or a worn distributer. What about changing to a lighter dist. spring and plugging the vac. advance?

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