Waterneck gasket info needed !

Sounds like warpage on one piece or the other to me .
Last attempt FYI
Ran in driveway 20 mins drove up and down highway near my house atleast 15 miles then came home checked it and dry ### was like oh ok D!m
Finally came out next day & dry drove to Chinamart ( Walmart ) for gear oil came home 3 drips came out
Water neck is new actually a decent cast alum ( Kat ) brand I believe
Oh well just ordered the gasket member recommended and if it works properly I will buy 5 more to keep in waiting should I need one for another project.