I am smoothing my firewall on my 55 this morning and was looking at two holes under the cowl vent on the firewall. One is about 3/4" and the other probably 1/8". They are side by side about 1" apart. Are these or any hole on the outside of the firewall used for the Wipers? I have ordered a new wiper assembly, but it won't be here till next week.
Thanks

 

The choke cable comes through the big hole on mine. Nothing to do with the wipers.

 

Thanks Chris, Yuor pics in your gallery helped alot.
Got to get back to welding now.
Later

 

The smaller hole appears to be a screw hole with the screw head inside the cab, possibly supporting the defroster ductwork.