I might have to do this someday on my GT. That looks very nice!I've just searched all 5000 of my Opel pics and my FSM and exploded diagram parts book and the OGTS site and I can't find a single pic of what the oem coolant lines and their attachment to the radiator looks like. I've been driving auto GT's for 40 years and getting replacement coolant lines and the fittings on the radiator has been notoriously difficult and basically impossible. Consequently, over the decades I have screwed barbed fittings into the radiator with rubber tranny hose clamped on. Usually I only had the short remnants of the oem metal lines, so I would flare the ends and stick them into the rubber hose, plus hose clamps.
Since then, I have deluxed my coolant lines and run them to a dedicated auto tranny cooler/rad with a fan and a thermostat. You can buy a kit from Jegs/Summit that gives you braided flex hoses and the cooler/fan. Something like this:
View attachment 444151
The pic above shows what the ends of your oem metal coolant lines "should" look like on a GT. The braided hoses have AN fittings and I install AN fittings on the tranny:
View attachment 444152
View attachment 444153
Instead of the silver cooler in the pic above, I bought a different, more favorably sized, black cooler with a fan and I installed quick disconnects....
View attachment 444154
View attachment 444155
Doing all of this frees up your radiator from having to cool the tranny also and, therefore, increases your radiator's engine cooling capability. The flexible lines also enable me to easily run both lines along the cooler left side of the engine, away from the exhaust and all the congestion on the right side of the engine and tranny.