For a DD, swap the c1 in and go ahead and get a new timing belt, water pump, and etc. Swap it in and maybe throw an intake and exhaust. Save your money after the swap and before summer upgrade cams, cam gears, new pistons and rods, valves valve springs etc and upgrade with a chipped and tuned ecu. MAKE sure that everything is tuned up properly. Save the money and the hassle of boosting it and build it. Because with really building it, its gonna pull really strong all the way through the torque curve, and you dont have to worry about turbo lag and that bs. C1. build it. and bam. A good buddy of mine has a teg with a fully built c1 and it is pretty fast. He has eaten supras, rx7s, 240's and all sorts of shit.