Do the research! I second the rebuild what you have. The stock stuff works great! More than likely your crank, rods, block, and maybe even the pistons are all still good. If not, make sure to replace with turbo parts. I personally don't believe in turning a turbo crank more that 10/10, hopefully unless you spun a bearing you can just polish it. You can find everything you need here. Don't be shy to ask questions, it might save you a headache down the road. If your not doing the work yourself, find a turbo buick shop/machine shop to do the work.