evaporative control system

this goes along with the fuel line question. Does anybody use the ECS on a 74 cj5 (ch 6 in the haynes repair manual)? Is this even necessary? Is there any benefit to puttting it on the new tub? My understanding is that it just filters the fuel that evaporates from the carb. I have the entire system but there was no vacuum line running to it. The filter obviously needs to be cleaned or replaced so if anybody has some info on where to get one that would be helpful. If i leave it off, whats the best way to block the lines going into the gas tank? Thanks.