AC Delco Corvette Master Cylinder thread size?

[findog78]

I'm doing a rear disc brake conversion on my 69 C10 and looking to mount the new prop valve on the bottom of the master cylinder instead of the side. Searching the web I can't seam to confirm the '82 corvette master cylinder brake line fitting size so I can buy pre bent lines. Some sites say 3/8-1/2 and 3/8-9/16 which I think is my stock C10 master? There is a bracket and brake line set at CJ pony thats say 3/8- 7/16 Inch and 3/8-1/2 Inch? There are also complete kits with master, prop valve (which I already have from my conversion kit), bracket and lines on ebay but I'm weary of fake ACDelco and junk parts on there. Can someone confirm the corvette master thread size please?