03-04 stingerGRT copy late model info?

I know somebody had one of these and I got some questions please. first off I know its pretty much a GRT and this is an underslung car. I have known of the guy that owned this car for years and he did pretty good with it and this is my first late model, I got his setups for all the tracks we would run so shoudnt need much there.
1. Should both front lowers be 17 5/8" long?
2. should the uppers be LF 8 1/4" RF 10 1/2"
3. should the spindle height be about 11" and right about 10 1/4 which would be close to GRT black spindles?
4. the underslung on the left side has been cut and lowered cause the car would go solid when it got up on the bars and bottomed out on the underslung. Is there any other known problems with these cars?
5. the front GRT bumper bolts straight butted up in line on to the frame. I worry this could cause the frame to bent in a crash easier by transmitting force straight into the frame. would the rocket style way of mounting where the bumper slides inside tubes welded to the car frame and has 2 "shear' bolts holding it on a better idea?

Thanks for any help I am trying to get as ready for race season as I can. Please only answer if you have personal experience with the question, THANKS again.

the lowers should be 16 5\8 left and 17 5\8 right and the uppers were both 10" mount on the inside of the frame, the underslung rail is all ive ever change other than brackets on ours, the bummper will be fine there, the bumpers give up way before the frame rails do normally but i did raise the mount on the right side so the bumper was much higher than they start out with, but the problem went away when we started using the newer grt bumper with built in rake from right to left...