Getting a lot of exhaust and CO in the cab with windows down

[Calif240]

Saw a few similar posts, but nothing really with any defined fixes... When my windows are down (I don't have AC yet), I still get a lot of CO and exhaust fumes that give me a headache if I drive too long. I don't have gaskets between the collector and rest of 3" TTI exhaust as my kit didn't come with them, so I was just going to install when I had time... I didn't think THAT small of a leak could lead to significant exhaust fumes coming in at 45+ MPH. I also have a few spots in the trunk that weren't fully sealed that I was reading about could contribute. Beyond that, do you guys know of any other areas that are common to get exhaust fumes into the cab? My firewall has no open spots and no holes in the floor. Tired of feeling lousy after joy-rides...

Thanks for any advice
Terry

[terrible one]

I have been slowly working on the same issue. What is your crankcase ventilation setup? I was running open breathers on both valve covers and after switching one of them for a PCV valve that helped a lot. I still have some smell but the other side is still just an open breather, I wonder if getting one with a tube going to the air cleaner would take care of the rest of it, making it a closed PCV system like the factory. 

[Ghoste]

You might be surprised how unsealed your floor and firewall actually are and how small a leak can inside, these cars trap a lot of high pressure air under the car.  Get those gaskets and make sure you have tailpipes going all the way to the bumper.

[twodko]

Install collector gaskets, seal trunk areas and if you're running any kind of exhaust pipes/tips that do not extend out at least even with the rear bumpers outer most edge, you could be getting fumes in through the trunk area because of running short exhaust tips. 

[Hard Charger]

trunk seal was my problem. got a lota stink from there.

[twodko]

Had the same problem years ago in another car.........turned out it was the mother-in-law.

[Ghoste]

But first you thought it was a dead rat?

[Dino]

I have been slowly working on the same issue. What is your crankcase ventilation setup? I was running open breathers on both valve covers and after switching one of them for a PCV valve that helped a lot. I still have some smell but the other side is still just an open breather, I wonder if getting one with a tube going to the air cleaner would take care of the rest of it, making it a closed PCV system like the factory. 

How about two PCV valves running both hoses to a T splitter on the carb?  Would that work?