Not at all, it's quite common for manufacturers to change OE part numbers as revisions occur. At Volvo we had a spate of thermal transmitter changes for the old 440 that saw 7 different part numbers for the sender units in about 18 months, each one gave a slightly different resistance. All about drivability complaints.....in the finish the dealers were pulling their hair out. Ford are also well known for this as they source parts from many plants they own around the world.
Will update when I get to the job.
