I have a 2001 YZ426. Dropped it off for a valve adjustment and the shop managed to wipe out the head in the process . A second shop disassembled and then did no more work for 6 months before going out of business. I now have a basket case. Thinking the cost of a complete 426 would be cheaper and leave me with a lot of spares to sell or use. Any idea what years are compatible bolt-in engine swap? Thanks for your help.