Which throttle body to use?

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I have a 409 ci small block that may occasionally see 7500 rpm. The intake will be the Edlelbrock Super Victor EFI manifold.
I have a stock single blade (LS1 style) throttle body from a GM Ram Jet intake, which I suspect is too small for my combo. I asked Edelbrock and Accel for manifold and throttle body recommendations, and Edelbrock recommended a four barrel type, 1000 cfm throttle body, while Accel recommended a three barrel, 1350 cfm throttle body.

What do you guys recommend?
What are your thoughts on my choices?

TIA!

[camcojb]

I have a 409 ci small block that may occasionally see 7500 rpm. The intake will be the Edlelbrock Super Victor EFI manifold.
I have a stock single blade (LS1 style) throttle body from a GM Ram Jet intake, which I suspect is too small for my combo. I asked Edelbrock and Accel for manifold and throttle body recommendations, and Edelbrock recommended a four barrel type, 1000 cfm throttle body, while Accel recommended a three barrel, 1350 cfm throttle body.

What do you guys recommend?
What are your thoughts on my choices?

TIA!

I had a 7500 rpm 406 with an 1100 cfm 4 barrel tb and it still pulled vacuum at wot, so it was a restriction, too small for the combo. The three barrel should flow more and work pretty well. I like the 90 degree Wilson adaptors and monoblade tb's for looks and performance, but it'd take bigger than 90mm to flow enough in your case. I think an aftermarket 90mm tb is about 1150 cfm, which may not be big enough.

Jody

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That's the kind of info I was looking for. Thanks!
As fas as I know Edelbrock doesn't have anything larger than 1000 cfm, so that explained their recommendation.
I really wasn't planning on the 90mm unless it worked out to really be the best. With the four barrel style I get to do the cowl hood thing for a reason other than looks.:screwy:

[Mike Norris]

Wilson Manifolds also has a dominator style throttle body in three version and flow up to 2000+ CFM. The middle version at almost 1500 CFM would probably work for you. I am a dealer for Wilson so just let me know if you need a price or more info.

Then we have billet LS style TB's up to 115mm if you decide to use an elbow like Jody mentioned.

Hope this helps.

Mike Norris

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Unfortunately, the intake I think I'm going to use has the 4150 flange on it, not the Dominator/4500 type.

However, I'm open to suggestions and any options for my setup.
The heads are Bowtie Vortec 180s, with some light porting done, so whatever intake I use needs to match them.
I'm not sure I'm willing to spend $2500 on a custom sheetmetal intake, but if you've got something more reasonable I'm all ears.

Is there any advantage to using an LS style TB with an elbow?

[Mike Norris]

I think the 4150 TB from Wilson is just under 1200 CFM. They do make an adapter to put a 4500 onto a 4150 flange that is 1.5" tall with and without a burst panel. Thay also offer a service to weld a 4500 flange to the 4150 manifold and will add approx 1" to the height of the manifold.

Just a couple less expensive options. The Accell three barrell is a good option also.

Mike Norris

[funcars]

With small vortec heads the TB choice is not as critical since they will limit how much flow and how many rpms the engine can use.