75 K20 chassis questions

[keniniowa]

Got the body off my 75 K20 plow truck today. Looking over the chassis;

One of the shackle mounts in the frame for a front spring is broken. Just replace it w/oem or is there something better to do with it?

The reverse-arch front springs are cashed. My brother has a farm truck that he put normal arched springs on. I'm guessing that raised it about 4". That sound right? Think I'd like it 4"s higher, not much more. Good source for springs?

Then blocks in the rear? Anything else other than shocks that needs done for this much lift?

Good shocks for a plow truck?

Needs a steering box. Can get a reman for $165 from my parts store. Is that a decent price? Is there anywhere to get a good(non-leaking) used one?

thanks
Ken