Well, If it is an exotic motor, (aircraft, diesel, euro-car, etc.) 15k might make sense. I check my clearances, and I have had to adjust before. I have seen pistons stick, bearings spin, parts collide, and all sorts of other headaches from people not checking. I have a six speed in my shop right now thats blown up because the previous mechanic failed to loctite ONE bolt! this same bike had black plastic parts plugging the oil pump, and the only way for it to have gotten there was from it falling in the cylinder spigot while the top-end was being re-done! These were mistakes made because of someone not being thorough and double checking thier procedures! My customer has had to pay me 3K in repair-re-repairing, cuase of lazy inept mechanics not making sure the job was done right! I will never be that kind of mechanic, because I refuse to assume it will be OK! I want to know that my motors are exact, and if it takes me 15 minutes and 5 bucks worth of plastigage, I'm willing to make that sacrifice!
BTW, we have many procedures which require checking things with parts that need to be replaced. We typically use the old parts just for checking, then use the new stuff for final assembly. It beats guessing that everything is OK!
