Finally installed BBK L/T's, have some questions though

I had the L/T's installed in two days, but the last three days were spent trying to get the front stock coil springs back in. I tried every single way mentioned on Stangnet and here and used the internal and external spring compressors. Maybe I messed something up or maybe it's because I have a convertible but whatever reason, the stock springs were not going back in. I had no time to buy and wait on lowering springs because my landlord told me I had to get it back together so I cut one coil off the fronts. They went right in thankfully. My first question is this. Since I cut one coil off of the front which measures out to about 1 1/4", should I cut the exact same off of the rear to even it up? I don't really want to lower the car much because of the L/T's hitting the ground so now I'm just trying to even the rear up. Again, how much should I cut off of the rear?
Second question, ever since I put on the UPR catless X-pipe with my stock mufflers, I had a bad rasp/really nasty sounding noise when I let off the gas and the engine begins to decelerate. At first I thought it was a leak at the ball and socket joints but even with the L/T's and catless H-pipe, I have the same noise. I gunned it tonight to see how much different the car is with the L/T's and I'm embarrassed to drive by other cars because of that rasp/leak sound after letting off the gas. It sounds like it's coming from the weep holes in the stock mufflers, is it possible for it to be coming from there? Or is it the common noise from catless h-pipes?