Winter or Tinkerage?

[Cold_Silence]

Hey guys, had a quick question.. Ever since i ripped my engine apart and did a head gasket job, [which is also when winter was starting] I notice a louder ticking in the engine.. In my opinion Its either be the valves, lifters, pushrods, or rockers.. I maybe thought i didnt tighten the rockers good enough put i did torque them to specs in chilton maunal. Its kinda scary though because if i let the revs climb pretty good you can hear it get louder and louder, and when at maybe 4-4500 rpms+ its very quick and barely loud enough to hear with radio off. At that engine rpm its like pfffffffffffffffffft so....

Second variable would be it is now winter, i live in Alberta Canada so it does get cold and my engine is getting old.. Hmm

Would you guys have any suggestions to what it could be? I made sure the pushrods sat well on the lifters etc but i may take my valve cover off again and double check everything.. I may also try synthetic oil thru the engine. Could something be dry that doesent get supplied oil? Loose rocker? Any opinions and suggestions would be awesome, thanks!

BTW The thing still runs like a horse though, doesent hesitate and fair amount of life left in her for 237,000 km's