No, all Roadrangers have synchronizers, at least the ones I worked on back in the 70's and 80's. The air-shifted auxiliary section has big brass synch rings that get clogged up with carbon deposits if the wrong lubricant is used in the transmission. If it's got hypoid gear lube in it instead of straight mineral oil, the synchronizers turn a deep black and the grooves in the synchro rings fill up with hard, black crud. Shortly after, it starts getting really slow to shift with the air system. I don't remember if the basic 5-speed main box is synchronized or not.
Jerry

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