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Discussion Starter · #1 ·
I've got a 88 GMC Sierra with a decently built 383 stroker in it. It has 700 r automatic trans and is 2wd. It has a Edelbrock performer dual plane intake on it and I was thinking of going with a Edelbrock carb but I'm just not sure. Is 650 cfm enough or should I go to 750 and with what carb builder? Thanks.
 

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Discussion Starter · #5 ·
So, smaller cfm will mean more torque and bigger cfm will give more HP? I'm looking for torque as it's a around town stoplight-to-stoplight cruiser. It's got a Holley 600cfm on it now but it's a 1997 model and I just think it might be time for an upgrade.
 

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Discussion Starter · #6 ·
Hey, thanks for the info everyone. That was an interesting dyno pull. Nice torque numbers.

I'll list what's been done to my 383, maybe this will help in carb selection.

It's a 72 Chevy high nickel block, scat stroker crank, 400 rods, Keith Black pistons. All rotating assemblies balanced. Block was line-bored, windage tray, high-volume low pressure oil pump. Cylinder heads were milled, bowl-cut, ported, polished and flowed. Stainless steel valves and Z28 valve springs. Chrome molly push rods with screw in studs, 1.6 roller rockers, comp cam and cam was degreed. Distributor has been curved to match the cam. Heads and intake match-ported. Edelbrock perfromer dual plane intake, 600cfm holley dual feed carb with 1 inch riser plate. After burner headers 700r 4 trans with B&M shift kit.

I've looked at Holley's website, Edelbrocks, and Barry Grants. All nice stuff, I just need to know what cfm carb to go with. Thanks.
 

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mattson70 said:
Hey, thanks for the info everyone. That was an interesting dyno pull. Nice torque numbers.

I'll list what's been done to my 383, maybe this will help in carb selection.

It's a 72 Chevy high nickel block, scat stroker crank, 400 rods, Keith Black pistons. All rotating assemblies balanced. Block was line-bored, windage tray, high-volume low pressure oil pump. Cylinder heads were milled, bowl-cut, ported, polished and flowed. Stainless steel valves and Z28 valve springs. Chrome molly push rods with screw in studs, 1.6 roller rockers, comp cam and cam was degreed. Distributor has been curved to match the cam. Heads and intake match-ported. Edelbrock perfromer dual plane intake, 600cfm holley dual feed carb with 1 inch riser plate. After burner headers 700r 4 trans with B&M shift kit.

I've looked at Holley's website, Edelbrocks, and Barry Grants. All nice stuff, I just need to know what cfm carb to go with. Thanks.
Cam specs?
 

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mattson70 said:
VE, is that volumetric efficiency?
Yep. Its a representation of how much the cylinders actually fill compared to their volume. A 5500 rpm engine probably is around 85% VE.

A Qjet would be a great choice. They are rated at 750 or 800, but they have secondary air doors that only open as much as the engine needs. That's why the same basic carb was installed on everything from V6s up to the Caddy 500. They're a great way of making sure you have enough carb without getting too much.
 

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mattson70 said:
VE, is that volumetric efficiency? So, buying a 750 cfm carb to put on a motor that eats only 600 cfm at 100% VE is probably a waste of money? Thanks for the help.
Like Curtis said, look at the picture of the 388 dyno sheet. The column "Air 1 scfm" is the measured amount of air passing through the carb at each RPM step.
 

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