How strong is the NP231, what will it hold up too? I've got the 32 spline tailshaft in mine already but with my 2.5l I need more gearing. I don't want to spend the money on a 4to1 kit and the 2low kit and blow the thing up in a couple years when I have more engine and more rubber under it. Its crazy what they want for the TeraLow kit and I'm wondering if I should just save my money for an Atlas 4.3 or a flipped Dana 300 with 4to1 gears. I'd appreciate any input and/or stories of busting a NP231.