I have been told that upgrading the Camshaft in my GM 454 will increase performance. What will this do exactly and what will the engine actually gain?

  • 10069286 block casting
  • 454cu
  • '90-'91 MY, Mark IV
  • 4-bolt
  • short deck
  • stock rectangular port heads

The engine has been rebuilt and bored .020" over. Otherwise stock. Hedman headers, 3" exhaust, stock intake manifold and 4 barrel Rochester carburetor.

Stock hydraulic camshaft.

  • Cam Style: Hydraulic roller tappet
  • Intake Duration at 050 inch Lift: 204
  • Exhaust Duration at 050 inch Lift: 209
  • Duration at 050 inch Lift: 204 int./209 exh.
  • Advertised Intake Duration: 273
  • Advertised Exhaust Duration: 298
  • Advertised Duration: 273 int./298 exh.
  • Intake Valve Lift with Factory Rocker Arm Ratio: 0.479 in.
  • Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.483 in.
  • 1
    As it stands, there is no way to answer this. It depends on what cam you are coming from (stock, but which stock cam), which cam you're going to, what type of heads, what modifications, and the list goes on. You'll need to flesh this out before someone can help you make an educated guess ... Even then it's an educated guess. Jan 15 '16 at 13:54
  • @Paulster2 Understood and thanks. Should this question be closed until it is revised with adequate information or best I get it entered right away? Jan 15 '16 at 13:56
  • If you have the info, add it now ... If you don't, we should put the close hammer on it, and you can come back and apply to reopen. Jan 15 '16 at 14:00
  • 1
    Also, please define what performance means to you. More peak torque, more torque under the curve, more horsepower?
    – race fever
    Jan 15 '16 at 15:00
  • Headers or stock exhaust? Stock intake/carb? Jan 15 '16 at 15:44

Essentially a camshaft alters how much air can enter the engine at a given rpm (thus moving your power curve around). Some aftermarket companies can sell you a more agressive lobe shape that will get more power at higher rpms with limited losses at the lower rpm - sorta a win-win.

With a hydraulic roller, you make power over about 4000rpm. If you want to make lots of horsepower, shoot for a cam that makes power to 6000rpm, knowing that below 2000rpm you might loose from what you have now. Do you tow?

I would start my talking to Comp Cams. Tell them what you want, and they will guide you.

Cam is the heart of the engine.

Go too wild, and you will hate your truck. Conservative is the rule.

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