You would only need to match the filter to that of the later model to be sure that the balance of the filter was a match for the '91+. I'd think that you would use a wired bulb/socket and not rely on the PC for power. I'd think it relatively easy if you had no filter differences aside from the "FULL POWER".
Wired socket/bulb pigtail and a correct filter - nearly done.
You might be able to compare the various filters using the 8C-4 (vicinity of a '90) and compare it to the year desired.
'90 DIC.png