I've seen "sandwich" plates that fit between the oil filter & the pump body with 3 or 4 ports for pressure & temp gauges etc. I've seen them for Jap import cars, but not found any for the Rover engine yet? I might try a search on buick 215 and see if anything turns up? This might be the easiest way out & I can still keep the factory set up & change it back easily if I want. Plus I can run an oil temp sensor too if I feel like it?

 

Well I finally got this figured out and have full real time monitoring of my oil pressure! I used a total of EIGHT fittings and 4 or 5 or which had to be ground & filed down to work for this application!