I have a 73 Blazer with a brand new crate 350, and running it with a carb and points. How do I get ride of these fumes? Will HEI help? Fuel injection? A cat? Or do I need a new carb? I want to run a soft top but with these fumes I'm afraid I'll gag my kids. I rerouted my exhaust to the side right behind the rear wheel. It helped some but still gets drawn in through the rear window when it's open.