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Help with my 383 Impala.

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  • #31

    Re: Help with my 383 Impala.

    Re: Help with my 383 Impala.

    I'd recommend a custom CC roller (about $300). The small base circle will help clear a couple rods if they're not already notched. For your 383, the 3196 lobe is good for the intake (236 @ 0.050 & 0.555" w/ 1.6 rockers) and 3317 for the exhaust (242 & 0.576). You could up it to the 3317/3318 if you got compression up closer to 11:1.

    I'd also recommend losing the power brakes and getting these on a 108 LSA. If you want to keep the power brakes, I'd spread them out to at least 110 and maybe 112. The torque will come on a lot stronger with the tighter LSAs, but it'll fall off earlier and not idle as well.

    Regarding your 1/4 mi performance, I got my 4000lb 383 Chevelle down the track in the high 12s at 108 with a 3:55 gear, 28" tires, 2200rpm stall in a TH350, Dart 200cc heads, and an Isky 280 megacam. Based on this, I'd say your setup might have left something on the table unless your gears are in the 2 range.
    Tampa, FL

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    • #32

      Re: Help with my 383 Impala.

      Re: Help with my 383 Impala.

      I've used those two Comp lobes on a bunch of 383's and really like them. Most of the time we run them on a 110 just to make p-v not an issue and keep people running power brakes easily but you'll definitely see an improvement running it on a 108-107 and still be driveable. Just need to at least clay check the p-v. Keep in mind if you run a small base circle you also want to double check your pushrod length.

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      • #33

        Re: Help with my 383 Impala.

        Re: Help with my 383 Impala.

        I've had no issues with power brakes running a 107, they've always worked well???

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        • #34

          Re: Help with my 383 Impala.

          Re: Help with my 383 Impala.

          Thanks for the info guys. From what you telling me, a custom ground camshaft is hardly more expensive than an off the shelf one. Cool.
          BS'er formally known as Rebeldryver

          Resident Instigator

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          • #35

            Re: Help with my 383 Impala.

            Re: Help with my 383 Impala.

            I think the 1st move should be more gear,in the 3.70 range if you run as a DD that should be a good all around choice.

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            • #36

              Re: Help with my 383 Impala.

              Re: Help with my 383 Impala.

              Thanks for the info guys. From what you telling me, a custom ground camshaft is hardly more expensive than an off the shelf one. Cool.

              Plus knowing what you know about your own spicific application allows you to optimize the setup for what heads and induction system you have.
              I agree with the boost in gearing as well.

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              • #37

                Re: Help with my 383 Impala.

                Re: Help with my 383 Impala.

                I've had no issues with power brakes running a 107, they've always worked well???
                Going with 3.7 gearing will help with vacuum as well (ie when you get off the throttle) Just be carefull in slow speed situations like parking lots!

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                • #38

                  Re: Help with my 383 Impala.

                  Re: Help with my 383 Impala.

                  BUT, remember, cam companies like to "recommend" camshafts they already have ground in-stock. :

                  AND, they love to go "up" on camshaft just a little over what a lot of engine builders would recommend.

                  Funny, virtually EVERY time you call Comp for a recommendation for a sbc/full roller....it somehow ends up at .630lift and whatever duration will "fit" the application......every time...... ???

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                  • #39

                    Re: Help with my 383 Impala.

                    Re: Help with my 383 Impala.

                    I've found most cam companies pretty conservative on cam choice really.

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