I ripped the soundfont using N64 Sound Tool along with the midis (which work fine) but a lot of the instruments are way too quiet and I don't know how to fix it. Can anyone help me or provide a better copy of it?
I already have this soundfont for Kirby 64. No idea if it's any better for you.
Volume issues can be fixed a variety of ways, either by normalising the source wav files in an audio editor, or by mixing tracks louder in a DAW (if you're using them in a sampler), it really depends what you're doing with them though.