The key is the vice jaws. Summit Racing makes a set of jaws that fit the fittings. I have used them on several race cars and on my Zenith 601. I used a dab of 30wt oil and push them on in one motion. My race cars were high temp oil lines with very high pressure. I'm more into aluminum flared fittings and hard lines now but I still use push lock for fuel lines and oil cooler lines.

I did find this neat tool while looking for a photo of the jaws. I might have to buy one of these babies
https://www.youtube.com/watch?v=MQMpcZNpOjQ