Yeah, they made a 2X4 version of the 350 4X4, which is the best bet for what you have.

If you start going into the carb, the suggestions for the carb cleaner are good ones, soak it well once it's torn down - check the diagram for places that might hide rubber materials (ie float needle)- carb cleaner will swell and eat the rubber up. Flush it out real good (spray carb cleaner works good for this)and start putting it back together - this way you are starting with a good, clean "base".