OK guys, sorry, I've been asking a lot of "Should I replace this part?" kind of questions lately, but here's another one.  I removed the charcoal evap can a few days ago and now I'm wondering what I should do with it.  I definitely need to replace the filter that's in the bottom, but I'm not sure where I can even get one.  I'm thinking I'll need to make one, but not sure what material to use.  Second, is it possible to replace the charcoal inside?  I've heard that a suitable replacement is fish tank filter charcoal, but I'm wondering if it's possible to get to the stuff without destroying the  thing.  Third, I think there's a check valve at the top of the can, is that replaceable?  Finally, what about replacement options (as a last resort)?  The parts houses don't seem to carry them and the ones on Flea bay are originals (no better than mine, maybe worse) so it would be from a catalog -- about $80 or $100.  Seems like I could spend my money on a lot more "value added" parts.....  I would like to keep the system intact, though.  This system actually does some good environmentally and it doesn't seem like it has a major negative impact on perf. I've already eliminated the cat and EGR so I guess I should keep something emissions related on this rig.  (My '76 L-48 came from the factory without a smog pump or EFE)

Some updates to this post: Rock Auto actually carries the canister (~$60) and the replacement filter (~$2).  I'd still be interested in folks' thoughts about replacing the charcoal, though, and whether or not that's needed/good idea....

any parts store should have the filters, the charcoal can get saturated, but I havent seen how to replace it other than getting new canister.

For what it's worth, my opinion is, it ain't worth the friggin hassle to cut the can open, dump the old crap, pour in the new crap(I have also heard to use fish tank charcoal), and insert the filter, then glue the can back together. Thass jest me, tho....I'm too dang lazy....
You can cut the bottom of the can off and replenish the charcoal if ya want...it's just a pita to do, compared to buying a new one, imho.....

Thanks guys.  I'm coming to the same conclusion about rebuilding the can.  Lot of trouble.  In fact I found an AC Delco replacement (on Amazon of all places ) for less than $50.  

I am having problems removing my charcoal can.  It seems to contact just about everything trying to come out.  I do not wish to bend my brake lines etc. to get it out.  What am I missing here?

It comes out through the bottom. I removed the vent in the fender to help with access to the clamp and hoses.

I took mine out from the top - BUT I have the engine out as well as master cylinder, washer fluid reservoir, clutch Z-bar, etc. etc.  I changed the hoses out a few years ago with all that stuff in and remember that it was super tight just doing that....

What year is it? Most come out easily from the bottom if you remove the splash shield...

Took mine out from the bottom. Much easier to get to as others have said.
Rodney