Never had much luck with Stage 2 Rockets, no matter what nubus Mac I used. Either:
the software was buggy
or the cards were defective
or the motherboard bus couldn't handle it
or MacOS couldn't handle it
(or all the above)
but they generally crashed within 5 minutes or less of booting and half the time brought the whole system to a halt.
Be advised, any of you buying this stuff off the internet that you may have the same experiences.
I eventually plucked the CPUs and RAM off the cards and dumped the rest off at the recycler.
Running 4 of them at once in a Quadra 950 was pretty wild, though.