This article describes how to belt drive just about any device like a welder, pump, second alternator, or whatever else you need to spin from the front of most any engine.
It covers a bush method of mounting a second drive pulley to the front of the engine and more professional methods also.
The article also has a simple methods of finding bolt hole centers (where to drill the holes) from tight locations without measuring. Much of the information comes after building over a 100 PTO mounts mostly in the field.
The article was originally written for boats, where we have to do this all the time, but it will work with just about any off the grid or survival situation or remote radio spot where lots of extra DC amps are needed.
The link is-
Second marine alternator
Hope this helps
Scott