If the donor bike is fitted with a;
DISC BRAKE
(or)
HAD A LINKAGE REAR SUSPENSION
(or)
WAS WATER COOLED
then the forks would not be EVO legal.
This is one of the reasons that the YZ465 fork/twin leading front end is so sought after.
It’s a big diameter fork that can be improved easily (springs, valving etc) and it has an awesome twin leading brake unit, and most importantly the donor bike was air-cooled, non linkage with drum brakes as original equipment.