Valve adjustment weirdness, valve adjustment Options

[Java2570]

Ok, I'm a newbie with a 1974 914 2.0L. I am replacing my heat exchangers and exhaust this week and while I have them off, I figure I'd adjust the valves while
I've got extra room to do so. So.... I spent time finding TDC notch on my flywheel and scribed a mark corresponding on the bottom viewing window of the trans.
I also have a red paint mark that was made on the fan that lines up with this as well.
When I go to adjust valves on #1, they are very tight and can't even get a feeler gauge into it to adjust. Then when I try to loosen the screw, it is making no difference in the looseness of the adjustment. What is happening here? Am I making some stupid mistake or is there something wacky going on? I've adjusted valves before on Karmann Ghias so I know how to do the adjustment basically. Also, the nuts are not
13 mm, they are 14 mm on this engine. I know the engine is from a 1975 car but I'm
not sure if the rocker arms were replaced or not......confused.
Am I doing something wrong here? Thanks!

[Dave_Darling]

Oh, and the rockers changed in 73 to the larger adjusting lugs, which have the jam nuts that take the 14mm wrench. That's why you want early rocker arms when you do the 911 swivel-foot adjuster conversion; the later ones don't fit the 911 lugs.

--DD