So I got it on. Had a heck of a time getting the parts correct. Several mistaken parts orders were made.
The first time around I ordered 5/8" brass tees and some 5/8" hose with some Gates PowerGrip clamps for 5/8 hose.
Along with the 5/8" barbs for the filter.
My factory hoses are silicone so I can't use standard worm drive clamps. Have to buy lined ones, or, these Gates heatshrink clamps.
When I got the parts, I discovered the factory hose going into the heater core is 3/4"
Back to the drawing board, I found a reducing tee. 3/4" straight through and 1/2" on the tap. I ordered 2 of those and 1/2" hose and the 1/2" barbs for the filter.
More powergrip clamps, now half for 3/4 hose and the other half for 1/2" hose.
Got them all in and the 1/2" hose is thinner than expected. Enough that the 1/2" clamps won't work.
Screw it. Its EPDM, Ill just use worm drive on it.
Then I start putting the tees in the hoses and find the outlet hose necks down once its out of the heater core to 5/8"
I was able to make the hose fit on the 3/4 tee thankfully. But this made the OD of the hose too big once it was pushed onto the barb, and the 3/4 clamps wont work on that side due to that.
I decided to make it work. I bought some hose clamps, and cut 4 of the 5/8" powergrip clamps to use as liners for the silicone hose, so as not to cut it.
So it was quite an ordeal, luckily I had the car downed for a major modification (I pulled the dash and did some things) so the fact that this took me 2 weeks to setup didn't do anything other than annoy me.