Yes
A 200 amp fuse in the cable to your starter solenoid is plenty.
My Comet is wired like your Mustang. 1/0 cable from the front to back with a 200 amp Mega fuse next to the battery.
Of equal concern is the grounding especially if you've got electric fans, hi amp ignition box, high amp draw starter, or other heavy draws. In the old days we all just welded a nut to the subframe inside the trunk and made a short cable, same size as the cable to the solenoid, and screwed it down.
More modern thinking, especially if an electronic fuel injection system might be in the future, is to run the ground cable, same size as the cable to the solenoid, to the engine block and then to the chassis at the front. Yes, it's cumbersome and heavy to run 2 cables from the front to back of the car. It is amazing to note how poor steel is a conductor of electricity compared to copper or aluminum.
Could help avoid electrical "gremlins" in the future.
Grounds,Grounds,Grounds!
I run + and - to the front of my car I did have hot cranking problems at first with a std size cable not sure exactly the size was not smaller then 1/0 I went bigger when I added a battery cut switch not had a problem after that. Not sure if it had anything to do with fixing my problem but it seemed to help with hot cranking when my high draw fans are starting at the same time.