300SDL OIL COOLER LINE INSIDE DIAMETER?

[dbdkemp]

for a 87 300 SDL
Without CUTTING THE rubber section on the oil COOLER LINES first
Does anyone know What size brass barbed Tee will fit ??

I need to put a Tee on a high pressure side to run to a centrifuge oil filter.
[U]http://www.dieselcraft.com
This seemed like the likeliest point for me to run off from without disturbing the rest of the plumbing. figure i can get a brass tee fitting and a couple adapters to run the line.
I could just cut the line and take it to match for sizes, but i would rather have the tee fittings and get it all done while changing the oil. measure twice cut once.
Thanks

ps sorry about the caps, kid in playing with the button over my shoulder

If you are interested I will be posting pics as i go - there is a handy spot to mount the unit right next to the ABS unit
Please mention my Name (David in Sacramento, CA) if you get one as I promised to try and bring referrals to them, they are local guys (Auburn, CA) and have what I believe is a great product. The Auto makers don't use these because they want the engines to wear out.