Where to connect preoiler lines?

I have a new preoiler pump to install on my -6A but unsure where to connect the high pressure output side. The input side comes from the bottom of the sump. This is an O360-A1A with oil cooler and oil separator already installed so some of the ports are already used. Any thoughts, please?

Not an answer to your question but the Lycoming Service Instruction No. 1241 covers pre-oiling the engine.

I'd suggest a steel AN826 tee at "B", the usual outlet to the cooler, as the flow paths would then be the same as normal flow, including filtration.

Thanks for the reply Dan.
Connecting to the 'B' location was my first instinct, too. That's the output going to the oil cooler currently. With this being an outlet port which is at oil pressure level from the pump,
I was unsure if it's suitable to back-feed into it in order to pressurize the engine. I'm thinking this port must be downstream from the oil pump and feeds the engine, so back-feeding it (with the engine off) would in fact feed the engine, as well as the oil cooler if I tee into it it.
However, there may be pressure loss if oil flows backwards thru the engine's oil pump since there's no check valve that I am aware of and there may be pressure loss thru the oil cooler, too.
-ChuckB.