Hello....I have the gas tank out and am sending it out to be cleaned, sealed and painted. Do I want to have some of the vents brazed shut...? If so, which ones...? Thanks...Riley

That depends on what you are going to with the car now (stock vs modified) or might do later, I have always found it's better to keep your options open by putting a short piece of hose on on the pipes you are not going to use, put a plug in the end and clamp to shut them off, the next owner will appreciate it too.

I was going to connect the one on top and close all the rest. But is there any reason to keep them open...?

Here's a very informative thread on 240's evap tanks. Lots of ideas and pictures.

http://www.classiczcars.com/forums/topic/17542-treating-insideoutside-of-gas-tank-with-por15-products-and-removing-evaporation-tank/

Well you need a breather of some kind whether it vents to the airbox or not, but the thread siteunseen just posted will answer a lot of your questions.