The guy I bought the car from said it was a complete 05 L32 drop in engine. I thought the back half was a bit low myself. I chalked that up to stock catback and the slicks. The 1/8 mile MPH was 77.51.
The catback on these cars are horrid. The mufflers drop to a 2' in and out IIRC. I know alot of people have told me a catback alone would probably help out quite a bit.