How important is that evaporation stuff?

Hi, I'm new to the forum and had a few questions. I got an 88 b2600, I had to replace the fuel pump, when I dropped the gas tank I found that the tank itself is in great condition, no rust inside or out. Except for the nipples for the evaporation system on the top of the tank. These are very rusted with some of them pretty much gone. My question is how important is the evaporation system as far as the vehicle running right? Do I need to buy a new tank even though otherwise this one is fine ? I appreciate any responses.
If it means anything, NH has no emmissions test.

Thanks
John

I am not real sure what you are talking about I will have to look at my parts truck when I go home this weekend. It has the bed off already. If no one else replies I will let you know what I find out. L888

you are talking about the vent ports right? or are the gas in/out ports rusted out also

the main idea is the tank needs to have a vent, because pressure builds up with heat, therefore the gas needs a place to vent. so as long as it is venting somehow, it will run fine.

there should be two hookups, and the one that is the tank vent is the white plastic peice on top of the tank, and the other one goes to the evap canister. if the white one is rotted out, etc. see if you can just find another at a junk yard, or mock something up to where it will vent the gases