bought a 3/4 ton 14b FF to go in my 1st gen Blazer. I know i need to move the spring mounts and at least one shock mount. My questions are: 1. What is the spring mounting center to mounting center distance for a 1st gen.? What is the tolerance from center center 1/8"-1/4" 2. How much tolerance do you guys think I could get away with side to side. anotherwords if I missed it by a 1/2" would everything still function ok. The tires would noticeably sit to one side. I should be able to get it dead nuts but just in case just wondering what I could get away with. 3. I'm doing a 4" shackle flip and about 3" blocks should I worry about rotating the housing slightly before welding on new mounting pads to improve driveline angles. Any Idea how much to rotate it? Thanky very much.