More Power from my 383 stroker

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Hi I have a 383 stroker built like a GM stroker
Cam 431 intake 451 exhaust
9.1 compresstion
forger 400 crank
Fliud Dampner
stock stamped steel rockers
Msd ignition
Gibson shorty headers.
Looking for advice to go up in power specialy low end
Aluminum head recomendation
Different cam
Also I was going to try a plow flow 4 intake
and a 0411 ecu
Please help
Thanks in advance
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Schurkey

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Hi I have a 383 stroker built like a GM stroker
Huh? All the parts you list are stuff GM doesn't use.

The GM "383" is a 4" bore, 3.80 stroke. Aftermarket "383" is 4.030 bore, 3.75 stroke.

Fairly sure GM doesn't use a forged crank and Fluiddampr.

Cam 431 intake 451 exhaust
9.1 compresstion
forger 400 crank
Fliud Dampner
stock stamped steel rockers
Msd ignition
Gibson shorty headers.
Looking for advice to go up in power specialy low end
Aluminum head recomendation
Different cam
Also I was going to try a plow flow 4 intake
and a 0411 ecu
Please help
Thanks in advance
Skip
Is the engine getting enough fuel? What is the spark advance curve?

Hard to beat Vortec heads for low-to-medium RPM power.
 

L31MaxExpress

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Hi I have a 383 stroker built like a GM stroker
Cam 431 intake 451 exhaust
9.1 compresstion
forger 400 crank
Fliud Dampner
stock stamped steel rockers
Msd ignition
Gibson shorty headers.
Looking for advice to go up in power specialy low end
Aluminum head recomendation
Different cam
Also I was going to try a plow flow 4 intake
and a 0411 ecu
Please help
Thanks in advance
Skip
You don't need an intake swap to build decent power. Proflow intake is going to require alot of modification.

The cam you have builds excellent cylinder pressure for low speed torque. 1.6 roller rockers added about 20 hp and matching torque across the whole rpm band on the HT383 test.

My 383 has ~200cc offshore aluminum head castings ported by Lloyd Elliot to ~210cc and 2 points more compression. Larger 218/228 @ 0.050 cam but Rhoads V-Max lifters. The Rhoads lifters knock my cam profile down to about 198/208 @ 0.050 at low rpm. I have 1.7 rockers for 0.578 lift.

I ran a set of the same 200cc aluminum heads minus porting on my 350 with a 215/223 @ 0.050 cam that was running 0.504 lift with 1.6 rockers. It made more power everywhere than the iron vortecs that came off it.
 
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[email protected]

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You don't need an intake swap to build decent power. Proflow intake is going to require alot of modification.

The cam you have builds excellent cylinder pressure for low speed torque. 1.6 roller rockers added about 20 hp and matching torque across the whole rpm band on the HT383 test.

My 383 has ~200cc offshore aluminum head castings ported by Lloyd Elliot to ~210cc and 2 points more compression. Larger 218/228 @ 0.050 cam but Rhoads V-Max lifters. The Rhoads lifters knock my cam profile down to about 198/208 @ 0.050 at low rpm. I have 1.7 rockers for 0.578 lift.

I ran a set of the same 200cc aluminum heads minus porting on my 350 with a 215/223 @ 0.050 cam that was running 0.501 lift with 1.6 rockers. It made more power everywhere than the iron vortecs that came off it.
What is the manufacture of the aluminum heads you used I was thinking afr, Did you have to used the Rhoads lifters. The 1.6 rockers is a great idea Thanks
 

L31MaxExpress

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What is the manufacture of the aluminum heads you used I was thinking afr, Did you have to used the Rhoads lifters. The 1.6 rockers is a great idea Thanks
About 20 different companies sell the same offshore casting including AFR. The AFR Enforcers are not drilled for the Vortec intake pattern though. Mine are Assault Racing. I bought them bare and built them with decent parts, did a little bowl and chamber cleanup and had a valve job done on them. The 2nd set I have on my 383, I let Lloyd Elliot port.

I did not have to use the Rhoads lifters but I wanted a stock like idle, better fuel mileage and a broader torque curve.

Edit-Here are some pictures of the 1st set. No port work, just bowl cleanup and a good 3 angle valve job.
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Valve opening with the stock GM Vortec cam.
0.418/0.424
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Valve opening with the 357hp SPO 350 cam and 1.6s I had in my 350 with them on it. Huge difference in the amount of flow getting in and out of the cylinders through the larger 2.02/1.60 valves. 0.504 lift shown. The 383 has 0.578 lift. 0.074" more than shown in this picture.
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L31MaxExpress

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This is a 218/228 (more like 224/232 @ 0.050 with the 1.7 rockers) cam on a 108 LSA and it idles practically stock with almost 20 in/hg of vacuum at 750 rpm.

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L31MaxExpress

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Just though I would share what the same Assault castings look like after Lloyd Elliot had his hands on them. They outflow any stock GM cathederal port LS head and some ported ones.

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