I'd believe it. Ronnie Duke is an SLP dealer here in Michigan so when I went to pick up a part, we got talking about his cars. His Trans Am holds the record for the fastest LS1 powered car, his record is a 8.52 @ 163 mph. The car still is still in street form, full dash, hell he even left the stereo system in it. Its also a twin turbo so I have no doubt Lingenfelter's can run that. Yet more proof about those damn spooly things. Check it out.
http://www.web-pace.com/ls1.htm