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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: sbx22 on June 20, 2011, 01:28:18 am

Title: Thinking of getting Holley 670 in place of old quadrajet
Post by: sbx22 on June 20, 2011, 01:28:18 am

I'm in the process of swapping out the old motor for a rebuilt. Been reading up a lot on carburetor choice. So I'm thinking of going the route of a Holley 670 street avenger. Truck originally had quadrajet in it. Is it a simple swap of carburetors? Will throttle cable, vacuum lines, etc. still work with the Holley?

Title: Re: Thinking of getting Holley 670 in place of old quadrajet
Post by: 1979C20 on June 20, 2011, 02:23:34 am

Vacuum lines will match, throttle cable eyelet may need modifying, and if you have the stock intake you will need a square bore to spread bore adapter for your local parts store, unless you buy an aftermarket intake with a square bore pattern and respective mounting holes.

Title: Re: Thinking of getting Holley 670 in place of old quadrajet
Post by: sbx22 on June 20, 2011, 12:59:19 pm

Thank you! It'll have an aftermarket dual plane, I believe edelbrock.

Title: Re: Thinking of getting Holley 670 in place of old quadrajet
Post by: Grim 82 on June 20, 2011, 01:11:16 pm

If you have a 700r4 transmission you will need the proper brackets to hook up the TV cable. You will also need to modify your fuel line and install an in-line filter.

Title: Re: Thinking of getting Holley 670 in place of old quadrajet
Post by: sbx22 on June 20, 2011, 06:26:05 pm

I have a TH350, does that mean I don't have to change the TV cable bracket?

Title: Re: Thinking of getting Holley 670 in place of old quadrajet
Post by: Psycho71 on June 20, 2011, 08:12:37 pm

The kickdown cable should bolt right up to the SA carb. Mine did. My advice, unless you have some mod's to the engine, get the 570. Less tuning will be required on a stock(ish) 350.

Title: Re: Thinking of getting Holley 670 in place of old quadrajet
Post by: Grim 82 on June 20, 2011, 09:49:20 pm

Psycho71 is correct about the cable and the cfm being possibly more than what you need, but you can definitely make it work. Where you run into trouble with the cable is when you have a 700r4 that requires the right geometry to function properly. You should be fine. The brackets that you will need to hold the cable will depend mostly on which intake manifold you are using, and whether you use a spacer or adapter, etc.

Title: Re: Thinking of getting Holley 670 in place of old quadrajet
Post by: sbx22 on June 20, 2011, 11:41:42 pm

Thanks for all the replies. This is what I'm getting, or should I say, being shipped in a couple weeks. http://cgi.ebay.com/ebaymotors/CHEV-350-330HP-CRATE-ENGINE-TUFF-DAWG-ENGINES-_W0QQcmdZViewItemQQhashZitem2564d371f3QQitemZ160605368819QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories Would you consider this a "mildly built motor?" I've asked Darl who is the builder, he recommends the Street Avenger 670 cfm. What do you guys think? I know that it might be a little on the larger end of carburetors but...

Title: Re: Thinking of getting Holley 670 in place of old quadrajet
Post by: 1980c10 on June 21, 2011, 12:49:26 am

I would consider this engine mildly built, looks like a nice solid running engine per specs.
In my opinion the 670a with the factory installed jets would be a perfect match to the engine.
I have the 670a on my 350 with a little more power and I needed to change to upsize jets, I have also tested a 770a with good results but just didn't want to lose vacuum.