Please take every precaution to prevent damage to your parts when sending them to us for work, or RA. Separately package heavy and lightweight items (or use heavy duty or double boxes) so they cannot bang together or be damaged by the carrier. This is especially critical with heads and pistons and cylinders. Install the pistons with rings in the cylinders and package each cylinder separately, then install in a larger box. Heads should be bolted together (1/4 threaded rod works fine) chamber to chamber, wrap with cardboard and put in a box. We can assure you that if you do not properly package your parts and they get damaged it is unlikely that they will pay for damage caused by your neglect. Even if they decide it is their fault you will be held up the time it takes "you" to settle your claim with the shipper, and that could be weeks.