what bolt lube to use

What does the factory service manual say?

Mymopar.com

Free download

I just looked and the FSM does not say anything about lub on the bolt threads.

Note the torque on a dry bolt vs a lubed bolt are typically different.

The same torque on a lubed bolt might stretch the bolt more than the same torque on a dry bolt. Meteorology of the bolt will be the deciding factor and what the bolt manufacturer says.

Just my 2 cents

Shoot, I want to check my 1970 Plymouth FSM now, I could've sworn it called for motor oil on threads for main and rod cap bolts. I'd check your link but I'm on my phone, don't want to deal with downloading and unzipping a large file.