thought of the mtx75 for mine ,have used the ib5 box from escort mk5 1.8 zetec just had to swop bolts around on rear of box for s1 mounting . back to s1 bc box now but will prob top out 125 mph and sound like its in 4th at 80mph flat out on motor way lol . 4.27 final drive for ya lol , wonder if any one sells brackets , shafts , and mounts in kit form for the average guy doing diy job at a good price . some one could make a mint !