All - After owning my 80 for over 2 years, experiencing higher than normal pressure when removing the gas cap the entire time, I tried many solutions. However, I've been reluctant to replace the charcoal canister due to the cost -- approx $300 (plus or minus), and it's a dealer-only item. Many of us have posted/read info on this thread: https://forum.ih8mud.com/80-series-tech/292965-excessive-fuel-tank-pressure.html I tried a junk yard canister from a 1997 80 with absolutely no affect. I tested hoses, attempted to test pressures, made sure the VSV worked correctly, etc. As best I could tell the system was at least functioning. After much research, I found this alternative canister for $36 !!! If the link gets stale, it's Autozone part VC120 for early 1990s GM cars with the 3.1L V6 (pontiac, oldsmobile). The dimensions were close enough to ours, so I pulled the trigger on a hunch. And it works beautifully! I wanted to run thru several fill-ups before I posted, and I can say that after 6 fill-ups, my 80 finally operates like a normal car (as the gas pump anyway). No sound, no air escaping, etc. It has the same style connectors and pulls in fresh air from the bottom just like the 80s. Using the highly calibrated "blow with your mouth" technique, I confirmed that this canister is almost identical to the stock 80s as described in the FSM. Minor details on mounting: There is no hose connection on the bottom like the 80s, so you can remove the hose completely. This replacement canister has it's own filter and cover on the bottom. In stock 80s, the hose simply routes down to the frame area. I assume to pull in fresher, cooler air. The diameter is just a bit larger than the stock 80s, but you can see in the pic below that it fits in the stock bracket, in the stock location, using the stock hoses. You'll notice that I used a ziptie in place of the bolt on the bracket - a longer bolt would be better, but I didn't have one around. And it's a tight fit, so I don't think it's going anywhere The "tank" port on the canister uses a larger diameter hose barb, but a little persuasion works. Info/links: How to test your canister from 1997 FSM -I suspect that the purge check valve in my canister was sticking. You should have suction into the engine on the purge hose as described in the link above. This suction should be able to keep up with vapors generated in the tank as long as the canister flows freely. I haven't tested this after driving up to high elevations yet, but based on my experience so far, I think it's going to do great. Hope this helps out the community as much as it's helped me.