I may be out to lunch here, but I do believe that I have a compatibility problem between by card and intake. The carb is a Rochester Quadrajet and the intake is an Offenhauser Dual Port intake. Something did not see right (still doesn't) so I used a carb gasket I had lying around that matches the base of the quad and layed it on the intake. If I am correct my secondaries and primaries should be separate, should they not? Just wondering if maybe this is the way it is supposed to be.

I do not believe so and am considering just grabbing on a stock intake for now. Looking for a second opinion. This setup was on the car when we got it.

 

The shape in the top of the intake is a function of air flow. The Air flow is a function of the intake design and testing. If you have a Dual plane intake you may have 4 separate bore with a single plane intake may just have a big square-ish hole in the top. There are times when an intake does not work with a given carb, but that are due to the secondary's hitting the intake and limiting how far they can open or you do not have a gasket that can fit and seal between the two. If the car is running good you have neither of those issues. If the secondary's were not opening you would have no power. If you had a vacuum leak the car would run like crap and stall every chance it got.

Even if you had one of those issues someone makes an adapter it sort it out. Weather you have the right intake for how you use the car is another thing. Most factory intake are good for all around usage but great at none. IMO there biggest problem is the weight. They are insanely heavy for what they do. That is just because back when the stock ones where built cast iron was super cheap.

If your carb is the original one, unmodified and the engine is stock then using an original intake may result in better daily drivability. (more like it was a original car) If the engine is not stock I would lose the carb before the intake as long as the intake match's what you want from the car.

You should find a model name of the intake and research what it is good for. Full Racing, Street racing, towing... I have seen people put racing intakes on non-racing motors and lose power and drivability.

 

Thanks for the input Goran, I had a look and both the primary's and secondary's were hitting the intake. I have no problem with the carb and replacing the intake was the cheaper route. I replaced it with a stock intake off of a 1980 Corvette 350 and the car runs 300% better. I am going to do some more research but I think this intake is for the Holley.

 

I looked into it because I have never seen one. Getting rid of it was a good move. Edelbrock did test on it back in the 70's and reported it their test Corvette 350 lost 45 HP when switched to a Offenhauser Dual Port intake. That was 1970's standards. I would assume you would show another 20hp lost vs a modern Edelbrock duel plane intake. That was with the right carb. One review I read said these intakes helped with MPG.

 

I pretty much saw the same thing. I did see some people that said they loved it, but each to their own. I still have some tuning to do, but it already seems to be running much better with the stock aluminum intake. Thanks again for the input. It is always nice to have a second opinion.