Raw fuel smell with slider open

[B_derK20]

Hi all. My '83 K20 makes me sick every time I drive it with the rear slider opened. I looked at the sending units on both tanks and there are 3 lines for each one. The large ones go to the tank selector valves I'm guessing and Im not sure what the other ones are for. The 3rd line on each sending unit has 4 inches of hose with what looks like an axle vent stuck into it. I'm guessing that's where the raw fuel smell comes from. My question is is this how GM built it? The truck was built in Canada and I can't see where it ever had one of those charcoal canisters by the radiator. Would putting one of those in and running the vent lines from each tank to it fix my problem? It's hot here and I really need that window open since I don't have ac.

Thanks!
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[bigwheel15]

Where does your exhaust exit?
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[tucsonjwt]

You guessed right. in 1983 3/4 ton pickups were considered "heavy duty" trucks and were not required to have a evaporative emissions canister. So, you have a short length of hose with a one way valve stuck in the end for venting purposes (yes, it is exactly the same as the rear axle vent - you can still buy them from Classic Parts.)
I bought 25' of fuel line and ran the line from the sending units to the rear bumper of my truck (terminating above the spare tire) and put new vent plugs in the end. This moves the gas smell from the cab area to the back of the truck. In the 100+ degree desert heat it really reeks of gas odor back there but it is better than odor in the cab.
See in the pic very far back inside the rear bumper for two light grey dots which are the differential vent caps used in the modification (I have dual tanks.)

[hatzie]

I've run em into steel lines brazed through the bottom of the air cleaner. Gets rid of the smell.