whistling question

Ok, so I finally got the Dart/383 on the road today. Seems to run ok. I did run into a few issues though. 1) Under full throttle, at about 3500RPM I frequently here a whistling noise that lasts a few seconds. Almost sounds like a loose belt. I checked all the belts and they are nice and tight with about 3/4" "give". It is definately coming form the front half of the car. It starts out loud, and then diminishes and goes away. The power seems down. Second thing is the car has a Dana 60 with 4.10 rear. "Supposedly" rebuilt with all new parts, clutches, etc.... I've done several small burnouts with the car in drive and it leaves two black tire marks. Done a few starting in 2nd gear, and noticed only right rear tire left a mark (like a peg-leg burnout). Put it in drive and did one more and again, two back tire marks! I don't understand. I jacked up the car and put it in neutral and turned the left wheel and the right wheel turned in the same direction like it should. Former owner stated that he only had about 100 miles on the tranny (rebuilt 727 with Transgo shift kit) and the rear. My combo is listed in a recent post. I guess I though this car/motor would have a little more "umph" to it. I really don't think it is liking the single plain and 650 Demon that much, big stumble off the line, but that is just my opinion. Timing is set at 36. Even though vac advance is connected, it pretty much stays at 36 from idle to 2500 rpm, maybe advances a couple of degrees. I'm trying to stay patient and tune this motor correctly, but right now when in the car I just hope no punk in a 5.0 pulls up next to me!!!! Please tell me where to start to get things on track! (sorry for all of the info, but today was my first day that I could really spend some time with the car and drive it for a while.)