You definitely need a turbo on your engine, which lacks hp without it.

See the 700/900 FAQ for tips. You can remove and rebuild the turbo for about $350, making it new again. You can do it yourself for much less. Removing it is not a big deal if you have normal sockets, floor jack, etc. although corroded fasteners can prove frustrating. If you do remove it, take it off with the entire manifold to replace the exhaust gaskets as well (cheap but needed). You will need the jack to raise the engine enough to separate it from the manifold.