Wiper Travel Issue- Adjustment?

[revitout]

Hi there i'm from New Zealand and just got me a 76 suburban chassis lenghtened 500mm with a 84 crew cab and short box, 400sb t400. Real good conditon. I have issue with wiper over traveling ,as in i runs over the screen edge on the drivers side. In the down position it is low as it can go. Is there any travel adjustment on the linkage?Are there different wiper arms for each side?- these look the same.It looks as though its been going on for a while as the window rubber has a wear groove. Cheers