79 toyota 4x4

ive got a 79 toyota 4x4, all factory origional by the way, ive got 33's on it right now, they came with the tuck, but whoever put them on didnt upgrade the gears...shes sluggish gettin on the freeway, Hates goin up most hills in anything other than first, and my top speed is bareley 65, id rather keep the 33's than go back to 31's, so what are my options? i know i need a different gear ratio, but what would that be? i figure ill need new ones up front as well, so im gonna go all out and want front AND rear lockers, who makes the good ones? if i eventually want 35's or bigger will i need new gears again? can i get bigger gears than i need right now and run smaller tires without ruining them? youve got answers?ive got questions, lets talk.