Bore-Max/Vantage use the 177 on the outlet pipe on their pumping units. I was skeptical at first but I haven't had any leaks with them yet. Figured they helped a little with isolation also. I use 77's for the rest of my oil lines. If I ever do have a problem with the gasket, I'll just put a 77 on it. Like Rooster said, it's loose when you put it on the pipe and you're thinking that it definitely is going to leak when pressured up.
