If you choose to replace the oil pump gears please do your homework on how to properly prime the pump prior to reinstalling. There's a great video on YouTube showing you a step by step, it's a great reliable resource.

And pay close attention to the beveled edges when reinstalling the gears, they should face out towards the outter cover.

Remember, you need to prime the engine, cycle the oil throughout the engine before introducing fuel and spark. I like to pull the fuel pump relay and crank it over a few times to get things moving.

 

timing chains are not "life time" haven't been since the 60 when the life span of an engine was 80k.
if you would like to strip the front of your engine down in another say 20-30k and do it all over again you can do that.