[motherHD]

looking for a street manifold that won't choke a ported RA IV headed 455 with possibly an" old faithful" hr cam. would love to find a dual quad that works....Been looking at the e-brock rpm.
what about cutting up an Offy 4x2 ? adding spacers under the carbs?

[tom s]

Im sure people will jump in.There is a 60 pontiac that ran in the 10s I believe with a Offy with a pair of AFBs.They actually run very good with not a lot of work.Tom

[HWYSTR455]

I've run an Offy 360 dual quad with 625 AFBs, on a roller 455, ran really good. progressive, divorced choke on the secondary, electric on primary, street car, drove in all weather. They have plates that are for different mounting patterns, have to pay attention to that when shopping used.

The new edlebrocks are supposed to be very nice, though I have zero experience with them.

http://www.edelbrock.com/automotive_...le_carbs.shtml

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[Jerry H.]

I've been running this Offy dual quad with AFB's on the original 389 in this 65 for 4 years. I'm running the tri-power cam with a set of 67 HO exhaust manifolds, other than that it's stock. It runs fine on the street and has been raced occasionally. No problems. Talk with Carbking on this board to get some ideas on setting it up.

[motherHD]

I stand corrected, I looked at the front carb's intake ports and assumed it was a limitation! I really like the look of the e-book dual quad too

[tom s]

The P-65 is not as good IMO.Tom

[61-63]

The advantage of the Offy over the Edelbrock is carburetor spacing. The Offy locates the carbs far apart, only 3/8" closer than do the real super duty intakes, whereas the Edelbrock jams then up very close to one another. You cannot use the '56/'57 Corvette air cleaners that the real SD sets used on the Edelbrock intake because the carburetors are too close together.

You didn't say what year your car is (or I missed it?) but an Offy set on a '61-'63 car looks almost like a real SD set. Here is a picture of an Offy set on a '62 Catalina, with spacers. The carbs are SD clones but generic AFBs look good too.

[motherHD]

Wow, Thank you for the replies guys! The carb spacing doesn't even look right on P65 IMHO, Dual quad is my first choice...Offy looks like the better choice...unmodified

[Tom Vaught]

Originally Posted by tom s

The P-65 is not as good IMO.Tom

X2

I have flowed both and the Edelbrock P-65 has induction restrictions that readily show up on the flow bench. The Offy unit is actually a very short runner manifold with a "divided wall" down the center of the plenum (with "open doors" built into the center wall for common signal communication).

As was said, a basic Offy DQ unit allowed a engine to easily run in the 10s.

Tom Vaught

[HWYSTR455]

Originally Posted by Tom Vaught

X2

I have flowed both and the Edelbrock P-65 has induction restrictions that readily show up on the flow bench. The Offy unit is actually a very short runner manifold with a "divided wall" down the center of the plenum (with "open doors" built into the center wall for common signal communication).

As was said, a basic Offy DQ unit allowed a engine to easily run in the 10s.

Tom Vaught

That's useful info! Those restrictions I'm guessing showed up in the 4000-5500+ range?

The Offy positions the carbs more inline with the head ports too. More of a straight-shot than the P-65.

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