Wrong carb for 305?

[gerretw]

I have a 68 C20 with a chevy 305 in it. The gas mileage is terrible. More like gas footage. I think part of the problem is the carb. I found the number on the carb, it is a 17085212 quadrajet which I find out is for a 454. I am in a quandary what to do - swap it out? Rejet it? Or is it in need of tuning?

However, I think that isn't the only problem. I smell gas when I drive around. It has a mechanical fuel pump. It also has a dual tank that's not hooked up, and I would like to get it working, however, that's another story.

Back to the fumes - any ideas where they could be coming from? Is there a return line to the tank? If so, where is it? I only see one tube coming out of the tank behind the seat.

Thanks for any help.

G