I have this proportioning valve that came in a GM box. The part number is worn off on the box, so I am not sure of the part number. The two female threads for the brake lines are 3/8". I was told that Corvettes and other GM cars use bigger lines and that all 3/8" are for Fords. Are there any GM cars that use the 3/8" lines? If so does anyone happen to know the part number? It'* possible this part just isn't in it'* correct box, but I have no reason to believe this is the wrong box.

Any info. on this would be appreciated. I have attached a couple of pics.

Thanks