I have a 1995 Suburban with a Crate engine about 50k on the engine 5-6 years.   I believe it has been leaking snice installed.  Always smelled antifreeze and when I removed the old fitting I found silicon rubber around the fitting ( god bless my mechanic).   I replaced the top hose on the original engine which was the nightmare expected (broke off).  I was able to get this one out without breaking. Installed the new quick connect fitting and new Dorman hose.    However, I noticed it has a small leak from the fitting.   I can't tighten it anymore so I am guess the factory tapped the engine too deep or it may be possible there is a small crack righ by the port ( hard to see in there).

So I have 2 choices,  leave it alone and wait another 5 years until it leaks too much or try and seal it properly.     In doing so,  I run the risk of braking off the fitting (which I can fix as well) and then the question is do I try teflon tape or a high temp permatex?    How do they both handle high temp pressure?