in a 75G?
All bullhead species get too big for 75gal. It's not unheard that these endemic bullhead species get up to 10-12"in aquariums and Yellow & Brown bullheads get even bigger, easily up to 16-20". Yellows, Blacks and Browns have fastest growth rate that they can easily get up to 8-10" in first year! Which that is why all bullheads don't live long, up to 5-8 years but average lifespan is 5 years.Some bullheads don't get too large for the 75g (Flat Bullhead, Snail Bullhead, Spotted Bullhead) and Yellow or Brown Bullheads would do fine for several years in a 75g.
AmCaleb, that's a good choice I loved my Greens, they just got too aggressive for any other fish and didn't do well in the 38g (it was too small) I had at the time.