Motorcycle Repair: oil pressure on 1987 1340 evo, oil drain plug, tank oil

Question
Good evening Mr Wells.
 I have a 1987 FLHTC. I have put about 3000 miles on it since it's last oil change. ( it currently has 13,000 total miles.When it is cold, the oil pressure is approximately 30 lbs at idle  1000 rpms. It decreases  to approximately 12 lbs when warm, but drops as low as 5 lbs at idle when over 180 degrees. Is this much too low? Please forgive my ignorance... this is my first Harley. I've been on Hondas for the last 35 years. I was also wondering about oil drainplug, and filter location... and how about oil capacity while we're at it.?I'm about due to start tinkering with this thing myself.
Thankyou for your time!
Sincerely, Al Peters

Answer
No, your oil pressure usually drops like that. The oil pump relys on RPMs to make pressure.
Oil drain plug is on teh bottom of the oil tank, oil tank holds around 3.5 quarts and the filter is located under the bike, infront of the rear wheel
Good luck and happy riding
Mike