A few rear suspension questions

Thanks. I like the calverts. That said I am on a budget and was looking to get THESE and just work any angle into the fabrication.. 5 degrees and call it good?

Since the sliders are probably going to have the back spring location in a different position than stock shackles (probably a higher mounting point) I was wondering if I should also adjust the height of the front bracket bolt hole to compensate. The thing is that I do not know enough about leaf spring geometry to make an educated guess. I am hopeful that someone much more knowledgeable than me can look at what I am trying to to and make a recommendation.