Hey guys, my son is needing a new rollover vent valve and seal for his 84 half ton.
Anyone know of a source for one that fits. He thinks the hole is 1 5/8" but is afraid
pull it out and measure it because it'll probably disintegrate. I've been looking online
for 2 days but no one includes dimensions. Any help is appreciated at this point.

check ebay, i think the one for 80`s on up jeep will work . A friend used one on his volare.

Any Jeep? What about the seal? The lack of information out there has been surprising.

this one may be the one I was thinking of, not for sure though https://www.ebay.com/itm/Jeep-Fuel-Gas-Tank-Roll-Over-Valve-YJ-91-95-XJ-86-96-ZJ-93-96/162257975536

Thanks for the additional info. Had ordered the same seal as what's in that ad. I figure if it fits the hole in the tank we're good to proceed with the valve too. It should be here Saturday. Once we check the fit. I will post here for future reference. Thanks again for responding!

OK We got a valve and seal that fits, basically it is a seal and valve for an 89 Jeep Cherokee. I believe it's the same one mopars4ever linked to.
Here is a link to the one we bought it was cheap at about $15:

https://www.ebay.com/itm/Jeep-YJ-XJ-MJ-ZJ-Fuel-Tank-Vent-Valve-Seal-Kit-J5360058-911-060-52018823/184159663034?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Here is a pic hopefully:

Mopar # for valve is 5360058 (sometimes shown as J5360058)
Mopar # for seal is 52018823
Dorman # for valve is 911-060

One last thing the hole in the tank is not 1 5/8" like we thought. When actually measured it is 1 3/8"

Thanks for the update

No problem! I allways appreciate it when someone follows up when they figure something out. I included any info I thought would help. LOL