I believe I'd make the pump fit the tubing, instead of the other way around. It's not chiseled in stone that what's there, thread-wise, has to stay that way. On the race engines, we made our own pickup assemblies, and silver soldered everything together, even where the inlet tube went into the pump. We also made one-way oil pan baffles with swinging doors to trap oil at the pickup in hard left turns.
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!