I don't know of a site, but Mr. Gasket used to sell some software called Desktop Dyno that let you do it, even had Ford 2.3s in it... Sometimes it was pretty accurate, sometimes it was way the hell off.
It's hard to find copies of it anywhere anymore, but you could probably download it via Kazaa or Limewire.
__________________ 1976 Ford Mustang II Ghia: 302 with a 600cfm Edelbrock carb, Edelbrock Performer 289 intake, Dynomax Blackjack headers, 2.5" exhaust with Flowmaster Super 44s. RJS 11-gallon fuel cell, C4 tranny, chrome 16" pony wheels, fuzzy dice, brown vinyl half-top, and painted in the tackiest color ever (harvest gold, that's why I call it "The Goldenrod").
Also have a 2003 Dodge Ram (lightly modded daily driver/tow rig/office/dining room/home away from home/workshop... I call it "The Big Blue Dawg".) | 
is there a site that you can?? 
