Where does this electrical box go?

Alternator is a Denso 210-0106
Used on 1986 or earlier Toyota truck. It's 60amp, but there are 120amp ones available. I got it with a lifetime warranty from autozone for like $65, don't remember exactly. The bracketry might resemble OEM, but it's from Mancini racing for this conversion. The loom cover is F6.

Denso 60 amp Alternator Kit

Techflex - Flexo F6 Semi-Rigid Wraparound Braided Sleeving