Help on aftermarket/stock torsion bars?

Recently i bought a 2" lift kit for my 1993 4runner, and the kit came with new torsion bars. When i had someone install the kit, they did not install the new torsion bars because they said that the bars dont really wear out, so instead they just cranked up the stock bars to give it some lift. I dont know a lot about torsion bars so what i want to know is if i should install the new aftermarket ones that came with the lift - is there any advantage to that? Or are the stock ones (cranked up) the same? Also, are the new torsion bars longer, to support the extra 2", or the same length as the stock ones? Wondering if i should return the ones i bought.