I have a '77 F-150 4x4, and need to change the c-bushings so that my tires don't where out on the inside. I have several questions...

1. I have a 4" lift and called around to several 4 wheel drive parts shops, and one says I need a 4 degree positive and the other tells me I need a 7 degree. I am thinking about going with the 7. Any suggestions or input on this??? I am also going to change the radius arm bushing while I am at it.

2. Do I have to support the frame when removing the front spring? If any one can give me clear installation instructions, I'd appreciate it.

Thanks,

Rich