i have a 71 914 and i do not know anything about the engine other than it is pretty clean from underneath and runs good. I am adjusting the valves and am having a problem with cyl#1 intake. at TDC if i put pressure on the push rod end of the rocker arm with a screw driver it feels like i have a hydraulic lifter. If i keep pressure on the rocker arm i can turn the adjusting screw all the way in and still have more than .006 clearance at the valve stem. if i leave it like this it does not run right and backfires through the intake so the valve is not closing. how should i adjust this valve. all the others seem ok. i am thinking i will back off the adjusting screw and without putting any pressure on the rocker arm adjust it to .006. is it likely i have a hydraulic lifter mixed in with the solid lifters?

I have never seen where there is a requirement to put pressure on the push rod when adjusting valves. It sounds like someone put hydraulics in yours. You probably have one weak lifter that leaks down and that is the one that feels funny. Readjust that one looser and warm up the engine and see if that makes a difference. After they are all pumped up, you should adjust them all again. I am not sure on the procedure for adjusting hydraulics except to do it with the engine warmed up and the lifters pumped up. Maybe someone else who has them can give you the procedure.
Tom