Mine has done that since I have gotten the car, and was worse when I put a tune on it the tunes for these cars make the cars throttle response very touchy you can email your tuner to have it adjusted to have less throttle response and it will fix most of it, I have just learned how to control it...
Who told you they are limited to 450hp? The build I am doing will be 700whp and no need for any engine nor tranny building other then the clutch and ds. These motors/ trannys have been around 1000hp with no rebuild.
That is my build in progress.. I threw it on there because I am lazy so I had everything together one night and put it there so when the build is complete I dont have to find everything and write it down. I have ordered most of the supporting mods I need to run near 700whp currently working...
I priced the swap for 5.0 motor from a reputable company that has done it and others. After all said and done it was 18k.. Just go buy a GT at that point.
"We will not accept a return of an item that is damaged or defective if it has been used/installed please inspect all orders as soon as you receive them and contact HERE within 72 hours."
So wait they want you to get a driveshaft that is supposed to work when its sold....inspect it without...