Are you sure its a 35? and not an early part of the year 36? from what I know 36 was the first year of the juice brakes... but they did make the high cab for the first half of the year so maybe they had the juice brakes...
If you look in the doors of a high cab 36 the doors themselfs will be framed in steel unlike the previous 35's and 34's...
Thats my best guess.. sorry for being late to the reply i dont stop by all that frequently... if it were me.. id save the whole truck!