RE: Rear plate frame
You might want to rethink the 90 mm throttle body. I was going to install one also but have found out from a Chrysler mechanic that they have been having issues with the 90mm as it is putting too much air into the motor. They have tried to retune the electronics to take advantage of it but it threw a lot of the other timings so far out the motor was stumbling over itself. Dodge now has an 85 that is working real well with the 5.7 and 6.1 that gives the extra power and is within the onboard electronics to handle. They (mechanics) are recommending the 85 for the Challenger. I already have mine on order.