Wow.. so you were able to vacuum out the system and refill via the reservoir completely and without opening the crossover tube and venting out pressure adding coolant through the crossover cap? After doing the procedure once, did you have to go back through the system again after heat cycling? Was the car running at the perfect temp after the first time of doing this? Usually during the OEM procedure, you are supposed to leave the reservoir cap on the whole time after topping it off, and only opening and adding through the crossover tube. Using the standard method can take hours, and sometimes you still have bubbles in the system that you have to chase after and repeat over and over until they are all gone.
My buddy used one of these tools on my 92 Thunderbird LX 3.8 engine, but that had a vent plug you opened and filled the system normally and literally all the air pushed out and it hissed quite loudly in the process.. it was amazing, and he had a tool that powerflushed the radiator first, which I was comfortable doing because I was doing the heater core a few weeks later. The 302 was a tad different but same idea and all the air got burped quickly. My Lexus SC430 has a fantastic design with the system and its super easy to bleed, just by leaving the radiator cap off and running the engine till the thermostat opens while the heater is on. After it drops, you add fluid. The next day, it will be a little low and add fluid to the reservoir, and may need to repeat once or twice and until it was done. The 4.6 32V engine is obviously different and is much more involving.. its amazing with a little bubble of air will do to the car. I read about people putting in the Griffin radiators and the car runs hot, and it was because after 3-4 attempts, it took another 2 attempts before the air was purged although I think the extra attempts were needed because of the extra coolant capacity.
If this tool works just as well on the Mark VIII, then its a game changer and Ill pick one up from Harbor Freight so I can have it when installing the Griffin I want to get in the near future, since the cooling system with that radiator will require more tedious bleeding. I want to be able to have the car run normal or even slightly cooler temps while having the AC full blast during 120 degree heat even going up a steep grade.. This car certainly has a ballsy fan, so it seems possible and logical since my Lexus SC430 can do this with the stock radiator. I am wondering if Ford techs use this tool, and bypass the normal shop procedure to bleed. There is a write-up on the Reische performance site that sells the 170 thermostats.
On a different note.. How is the cooling of the second gen Marks with a cooling system in good shape? Are you able to run the AC full blast when its 115-120 degrees out, and run the car up a grade when on a trip, and not have the temp gauge climb rapidly like the first gens do?