I am relocating my battery to the passenger bin. The power wire I am using is 4AWG, which will probably be more than 10 feet in length from the battery to the remote terminal up front in the engine bay. A 150A fuse will be inline with that wire close to the battery. Can I safely use this wire, or do I need to use thicker wire?

 

That is exactly what I did on my FD, and I was pleasantly surprised that the 150 amp fuse was more than sufficient to run the starter even when cranking the motor over and over why trying to tune the cold and hot starting.

 

The 4 gauge is probably fine, if your paranoid run 2 or 0 gauge, sometimes though its hard to run that thick wire so the 4 gauge is more feasable.