Using threaded fittings under the pushrod cover usually causes an interference problem between the line and the sheet metal. It's a lot simpler to install a brass 1/8" pipe thread plug into the block with a 3/16" hole drilled into it, and solder the line to the plug. It's a lot less likely to leak coolant into the oil that way, as well.
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!