What’s everyone using to fuse between the alternator and starter relay

I did the ammeter bypass on my 68 and currently have 6 gauge wire from the 60 amp alternator, to a 80 amp circuit breaker, then to the starter relay. My problem is the circuit breaker is tripping on hot days (I believe the breaker is faulty, tested with another alternator). I would like to try another way of fusing the charge wire and would like to know your ideas. Fuseable link, another brand circuit breaker, mega fuse, none?

Thanks!
I have a 60 amp alternator and a 70 amp CB mounted next to the battery, has never tripped.
Even with the factory A/C on.