I know a guy who claims 74......I used to run with a guy that had 5.7's and he'd hit 70-71 so 74 sounds about right with 6.2's. (these are "good day" speeds IMO)
Mine is listed here and on eBay, eBay ends tomorrow evening. Mine is the one referred to above. Look ay the pics in my listing here there is a pic of the speedo and tachometer at w o t.