What you could try is extending the wiper linkage by another 1.5" like the nova boyz do.
Simply take out the wiper linkage, then cut the wiper linkage from the motor to the centre wiper and weld in another 1.5" extension from the drivers side linkage. This will give enough sweep to do the whole windscreen hopefully!
Note: I have not done this, i'm only telling you how the nova boyz have done it, you may need to weld in only .5" or a 2" extension, i do not know the exact size you need.
Hope this hlps you mate
"The Not so Fast but Furious"