Hey all. Uncovered the entire maintenance history on the truck (96 LX450) while ordering a heater hose today at the local dealership. Looks like 12k ago the head gasket was done and the part number they used to do the work is listed. So, a couple of questions. I saw that these have been redesigned (more than once?) Were there new part numbers when redesigned? Also, is there any history of how long these last after replacement with a redesigned part (i.e. is there still a significant rate of failure in a similar time frame to the original part number after replacement?) Sorry, left the part number on the desk at work. Will update when I get it.