Am going to get my timing and valves done this Monday, was wondering if I should get new injector tips? Heard something about doing this, my truck has 190k on the clock, was wondering if it is time to do this? I am by no means a diesel mechanic so I dont really know what it is supposed to do and sound like, I think it runs pretty good though. The valve and timing is going to be $125. 00 does this sound about right? Thanks for any info you give, Alex