Originally Posted by Curt B.
I'm pretty sure the original carraige bolts are 7/16"-20 NF threads. You can make square holes by drilling the corners with a small drill, then drilling the center and finishing with a file as seen here:

http://s176.photobucket.com/albums/w186/curt160/mods/?action=view&current=frontplateholes.jpg

See the tech tips for a template.
Curt,It's possible they are 7/16. I admit I was using a Master Parts Catalog that only went to 1951. smile By the way, I liked how you remade your shift box for manifold clearance.Very nice.


Drew