Desperately seeking a drain plug!

[sandalscout]

Okay, I have an 88 Cherokee with a 4.0 in it. My radiator is apparently NOT stock for the majority of the jeeps out there. It has metal endtanks, and Napa says that they have a metal end tanked radiator in their system, it's the "heavy Duty" version, apparently for towing and such (I don't have a towing package though). The drain is in the side, apparently they are normally in the bottom for the Renix models.

Anyway, the plastic radiator drain I had was found broken and leaking recently, so in the process of replacing it, I did my open loop cooling conversion. That all went great, but I CANNOT find a replacement radiator plug. Everyone is trying to sell me a brass petcock, and it's not the right one (won't thread). I was told that the brass petcock is for the plastic endtanks. The local jeep dealer only lists one radiator for 87-89, and the plug for it is WAY to long and the threads are too big anyway. I got a 10mmx1.25 drain plug (Toyota truck) and it's REALLY close, but the thread pitch is off. The 1/8 inch petcock (I don't think that it's actually 1/8" on the sleeve, just the inner part) starts to thread as well, but gets REALLY tight way too fast.

Does ANYBODY have any idea were I can look for this, or have any experience with this? I'd almost think that someone upgraded the radiator to something else, but it's a perfect fit, and it doesn't have a filler neck, so I'm sure it's stock.

Thanks in advance!

[sandalscout]

Just in case anyone else runs across this, NO ONE could find the plug, not the dealer, not any of the local autoparts stores, not the local radiator shops, nothing. I'm sure someone makes the correct size, somewhere, but I can't locate one.

I ended up taking a 5/16" nylon bolt that was .5" long, coarse thread, and putting a new gasket washer against that. Seems to be working great, and if not, I know what size plug to get now.

Now to sort of the massive leak that developed somehow (somewhere else in the system)! bleh, it's always something.

[motomech]

If it were me i think i would go get it welded up and if i need to drain the system i would pull the bottom hose and drain it that way