Over the winter I took out my 535 engine and changed all the gaskets. I noticed the engine now has a ticking sound that I have never noticed before. Two things are different I installed bosch platinum 2's and I found out that this engine has three different timing gear and oil pump gear combinations. I used a larger gear and chain on the oil pump. Could either of these cause the noise? I also think when the engine is at TDC the valves on #1 are not open all the way. Could that be the noise? Where should I start? The engine has a slight miss at idol.