Took aluminum cylinder head into shop for repair of valve guide after calling first and told no problem, upon taking part to machine shop Jon very short with me but said part would be repaired in 3 hours, figured must be having a bad day, but ok we all do. After returning to pay for and pick up was told head cracked, but instead of stopping to report this to customer, they forced guide in head and broke the head, I asked to see it please, it was then dropped on floor, head was not cracked, was inspected before dropping off, the break was fresh, when I told Jon this and that I have been a certified master tech for over 35years and this part was installed incorrectly he said f you get the f out of my shop