The cheapest option if you have fabricating/general skills is what darky mentioned. If you dont want to go that route here are the more expensive options but with the benefit of mostly every thing being done for you.. besides tuning.. http://www.extrudabody.com/servlet/the-335/Kit-cln--BMW-M42-fdsh-M44-Kit/Detailhttp://www.dbilas-shop.com/Products/Throttle-body-kit/for-Racing/BMW/Mutli-throttle-intake-system-for-racing-for-BMW-318is-E30-E36-1-8-16V-100kW-M42B18::8580.htmlhttp://www.gttechnic.com/catalog.htmlYou will probably have to buy one of the Kits above as Itbs Rarely Get resold