there is a fair bit wrong that engine should be close to 150 mph 9 flat just a comparison my sb at over 3550 lbs runs a 9.57@142 mph witch shows close to 800 hp ,get your box and converter checked for crazy slippage or something going on

1.37 60 ft [email]6.0@113[/email] [email]9.57@141[/email] 408 glide 3550lbs
new video http://www.youtube.com/watch?feature=player_embedded&v=Xvq3ZObywQE