1973 225 valve adjustment help!please!

ive owned nothing but hydraulic camshaft engines(318-360-383-400-440) and i now own my first 225 six EVER ! anyway ,the engine is a 225 6 bolted to a 3 speed manual. it has 146,000 on it and it runs fairly well, but after it warms up,it sounds like it is about to come unglued. all the info i can find says that it has solid lifters with adjustable valves.i have never had the valve cover off but i know it to be the original engine. it has plenty of oil pressure and does not smoke or misfire. is this ticking the valves out of adjustment? what is the simplest/best way to adjust the valves and what lash do i set them at? i thank everyone in advance for any info THANKS!