Can any one tell me if their was a test done with, lets say the closed air filter intake versus an open element (360 dergrees) in performance" I have a 1979 L-82 auto with headman headers and 2.5"dual exhaust

I'm not aware of any tests done, but there are a number of factors to be aware of, and the factory approach is a compromise at best.

You can have a completely open air cleaner, and it will have less restriction of the air flow, but will be sucking in hot air from the engine compartment, which is less dense and can make less power, but being heated, will help reduce emissions and warm the engine quicker.

An air cleaner that is closed, but has ducting to draw in cold air from the outside, whether through ram air effect or cowl induction, will have a cooler, denser flow of air for better combustion and better power. This can increase fuel consumption, emissions and take the engine longer to warm up. This all assumes everything else in the engine being equal.

As I said, the factory makes many compromises in this...some by law to meet the emissions requirements and balancing that off against what Corvette drivers want...performance. These different goals are often in opposition, hence the compromises made.

Many car owners I've seen (not just Vette owners), remove ducting from their engines and put custom air cleaners on for visual effect, but I wonder if they're actually gaining any performance (outside of their many other engine mods). Chevy gained something like five horsepower in the L48 in '79 as opposed to the '78 L48 just by adding the second cold air duct to the right side of the air cleaner.

In my '78 L82 I noticed a difference just by changing from a standard type air filter element to a K&N low restriction air filter with the same air cleaner assembly with duct work. I also noticed a similar gain in my '02 Lincoln LS by putting in a K&N flter as well.

It would be nice to see some truly scientific comparisons on this. I'm not sure how well it could go over, especially if it showed many custom additions or changes really don't help much or at all. It's like arguing whether an STP type product really helps compared to just using a heavier grade viscosity oil. Everyone will have their own opinion and data to back them up.

took the duct work off my 79 L-82 last spring for some minor repair at my shop. the increase in power was dramatic. ran better too. left it off.
I am looking for an open air cleaner that will fit. concerned about the location of the distributor.

The ducting is originally there with the purpose of controling the air temp going into the carb. Notice the tube going down to the exhaust system stove. The stove picks up hot air from around the manifold. The tube carries the hot air to the vacuum controlled air flap. The flap mixes hot air and cool air coming in from outside. This maintains the constant air temp into the carb. Constant air temp allows for better fuel control and emission control. It also is a part of the cold warm up and affects cold and mid temp operation.
Many of our Chevy customers flipped their air cleaner lid upside down to allow more and cooler air into the engine. This did help their power. But then they complained of hesitations during cold and warm up operation. This can be corrected with choke tension and pull off adjustments.

Some cars will see a noticable difference, others won't notice much. Perhaps the engie is already doing all it's capable of in it's present form. Perhaps the intake air has been choked, and the car will perform much better. It depends on your engine, intake, carb, and exhaust system. (If it won't flow out, you can't get more in.)

I don't recommend doing this for long, or in dusty conditions, but here is a quick test. Take the air cover lid off after the engine is fully warmed up, and drive it. If it runs better, think of which mod you want to do. If not, put the lid back on and forget it.

Ken Styer