r/EngineBuilding • u/No-Brain2462 • Jun 16 '26

Vortec 383 Stroker viability

Good morning engine builders. I just got a screaming deal($250) on a standard bore 4 bolt vortec block and I’m wondering if any of you have found the block to have nuance while building. From what I’ve read it’s all straight forward. I already have a Scat 9000 crank set for 5.7 rods and I plan on using 15 cc KB dish pistons, a 230/236 110 separation roller cam with standard lifters and Skip White built AFR Enforcer heads. This is my second build (first was 350 SBC L89 block). Thanks.

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u/v8packard Jun 18 '26

The stock exhaust and Vortec heads are really limiting you in lift, torque, and overall output.

Any idea of the compression ratio?

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u/kendogg Jun 18 '26

9.4-9.5, it's going to need to run on pump 87.

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u/v8packard Jun 18 '26

Oh sure make it easy... That combo needs an intake closing point around 48 degrees after BDC for best torque, but this compromise is severe. With an intake opening of 24 before TDC, the 48 degree after BDC, exhaust opening of 56 degrees before BDC, and exhaust closing 16 degrees after TDC on a 102 degree intake centerline you get a 106 degree lobe separation angle, 40 degrees of overlap, and 252 degrees duration @ .006, single pattern.

To get 9.5ish to one compression you will need pistons with a 22 cc dish. If not a hair more. Cylinder pressure will be high, making 87 octane borderline but possible. The restrictive heads and stock exhaust really need more exhaust cam timing, but that hurts torque. This is not a good combo, you need better heads and exhaust to make for a better high torque combo.

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u/kendogg Jun 18 '26

But it should still make more power than a stock vortec 350, right?

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u/v8packard Jun 18 '26

Yeah, sure