I checked ATP turbo (Garrett distributor), Turbonetics, and Precision Turbo....zip. I found some on ebay (search "turbo blankets on ebay"...don't know how to liny). Says they fit gt28 housings. I've used them on an older, single turbo application Z where underhood temps were a serious consideration. OverZealous(CT) explained it much better than I can, keeping underhood temps down as much as possible is all around beneficial. Check em out.