390mm is an approx length I'm sure they'll have varied by +-5mm or so, no idea. I could go measure my '92's I guess.
But yours is a 1994 when the rest of the range was getting suspension and the frames corrected for it I figured the '94 Blizzard was not designed to be a front suspension bike, a lot from the pictures) so still designed around the ~390mm rigid length. 420mm would certainly be long for that year and up there in the Downhill fork length and ~405 would be a more 'suspension correct' length.
ok, figured I would go do it properly. Zoomed into the picture in the catalogue to get the fork in the whole screen. Used my on screen ruler (MB-Ruler) and measured axle to ~bead seat position. This should equal 279.5mm
Measure axle to crown (both direct and inline with steerer tube)
and we get 385/380mm length. Error on that, I'm not going to work out

But small enough to be certain they are original length forks before suspension corrected lengths came about.
They would originally have been some very nice Tange Prestige Superlight forks at 720g.
Should have done that in the first place for you
