ZM Radiator Diameter Overall Aluminum Review

Everything perfect at first glance. Nice thick cast but as another user pointed out the threads are NOT 1/8 NPT. Now I can find a faucet or stop at a mechanical shop because I'm not that size.

I used it on a LS swap, the cap is junk but the unit itself is cast aluminum and works as it should, it's heavy to screw up a cast aluminum product like this. I wouldn't hit it with a hammer or anything, but put a decent cap on it from a stock 1965-1998 Chevy radiator and everything would be fine.

I probably had a casting/thread processing error. I tried 2 different 1/8 NPT nipples and 2 plugs I had lying around to make sure and none of them even started the threads, checked, it's threaded and doesn't look chipped or damaged. Not sure what's wrong with him. I'll try tapping it and see how it goes.