First, I want to run -6 hose from my mech fuel pump, upto the carb inlet.. Anyone know what size the Qjet carb inlet is, so I can get a -6 to ? adapter?

Second, anyone know what size/length bolts for the QJet? Are they 1/4-20 like regular carb studs?

Yes, the hold-down bolts are 1/4-20. Length is something you'd have to figure out based on your gaskets and such under the carb. I just carry it into the local Lowes with the gaskets and start shoving bolt though it to see how much thread sticks through. About half and inch past the bottom of the gasket will do fine.

Pretty sure the threads on the stock fuel inlet are 3/8" NPT, but don't quote me on that. You would think I'd know that off the top of my head, but I don't.