I started a thread about the different versions, but between the PCB population inconsistencies and labels (even when they're present on a card), it really comes down to what secondary label was affixed to the cardboard...unfortunately.
That said, your board's date of 1998, and the introduction of the L2 G3 on early 1999, I'd say it would be a safe bet that it's one of these (taken from a WaybackMachine capture from February 1999)
At one point the on-card labels briefly differentiated between cards only supported on 54/64xx/55/65xx Macs and the 4400. This is further
compounded by the lack of early-version support for
clones based on those architectures, respectively... hence my comment about only really knowing based on what label came with the box (not the slip cover, but a printed label on the cardboard).
The very last revision of the cards, I believe, we're compatible with all Macs and clones that used that specific L2 cache slot, even, bafflingly, the Power Computing PowerBase, which has a daughter card CPU... ¯\_(ツ)_/¯
At any rate, unless someone with a more thorough sheaf of evidence pipes up, I would think it safe to test on one of the Macs listed in that image/first round of compatible models.
Drivers are available on MacGarden, but it should boot without one, even if you don't get a fully featured experience.
Let us know which it is if you try.