Inverted flare? Most oil pressure lines use a 1/8" compression fitting/1/8" pipe male fitting to adapt the small plastic or copper line to the port in the block. There is also an oddball crimp-type fitting with a male thread that's a one-time use thing, but it requires a special adapter fitting to crimp the pointed end of the nut into the tubing on the first installation. After that, the nut stays attached to the oil line permanently.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!