You may just want to give up...I've been trying for 3 years to figure out if anyone has a fuel injected TR that was put on the road before mine. So far, I haven't found anyone that has one. I've found a few with lower build numbers, but they were all sold long after mine (some of those took months or years to be sold.) Therefore (in MY opinion anyway), I consider the put in service date to be more important.
Because these cars were built among all the other regals, and GM didn't keep records of which were which, if you factor in all the MIA regals (wrecked or stolen, etc) it will be next to impossible to figure out which "number" yours is!