Been there, done that!!! A few years ago when I installed Lamb struts and R&P steering in my car I thought I had everything blocked up to exactly where I wanted it. I also bought a deepened truck pan for the rear sump. When I got it all installed and the engine installed I had very little clearance between the pan and the floor. I had to do 2 things to get slightly above 3" clearance. I had to raise my engine and I had to section a slice out of the pan. I was using Andy's engine plate so I built my mounts so the plate rested above the frame rail. I redid the pan and extended the sump forward so that it holds the same amount of oil but it is not as deep. The result is I barely have 3" of clearance. I also installed a front air dam on the car and I barely have 3" of clearance for it also. The car sits nice and low in the front but to get the rear as low as I would like for it to be I would have to redo the wheel wells because I currently just barely have clearance between the tire and the top of the tubs.