WMD,
Like Berger said, I think removing the radiator will definitely give you more room to work and would make the valve adjustment a bit easier but I do not think the added removal of the radiator will shorten the time needed to adjust the valves time wise. Doing the valves with the radiator in place is a little trickier and does require more patience but removing the radiator just allows more things to go wrong or break in my opinion. If you do as Ken said and grind down an allen wrench to access the valve cover screws closest to the radiator and have the motion pro bent feeler gauge the valve adjustments are not that hard to do... you just have to have the right tools for the job :wink: Be patient and take your time and you can adjust the valves just as fast or faster than removing the radiator IMO....
Regards,