Well that was rather anticlimatic. · 10:36pm Sep 29th, 2017
Followed the manual, popped in the Evergreen Spectra 400 in place of the old CPU, saw the BIOS detect it at ~400mhz... and lag.
TONS of lag.
Windows XP does not seem to like the thing.
Like as in, going from 166mhz to 400mhz ended up being a speed downgrade.