Yes, the pin needs to be pushed in to use the full flow filter. No, I DO NOT recommend trying to do that. The pin will be extremely tight, and it will require some vigorous hammering to make it move- - - - -possibly causing the block to crack. It would be much safer to pull the plug out of the block by drilling and tapping it for a piece of all thread rod, and using a piece of steel tubing, a nut and a washer. Then, thread the hole for a screw-in setscrew to block off the oil passage from the oil pump to the main oil gallery. Use red LocTite on the threads to make the plug a permanent installation.
Send me a private message- - - -I have a full flow filter canister, with lines, that I'll never use.
Jerry
Edit: It might be possible to push the pin in safely by using a big C clamp, or something similar like a ball joint press, with the oil pan removed first.