I'm looking at building my own suspension set up. My dad and I bought a Rustys 4 1/2 inch lift. But I'm looking to remove the rear suspension with a long arm kit. I have access to a lathe, steel rods and taps. However I don't know what I should do about spring mounts on the frame to replace the leafs with coils. Any help?

there's lots to take into account while building your own setup like anti-squat so your rear end isn't sitting on the ground every time you accelerate.

best is to get onto pirate and read all the build links for that fabrication.

or you could just buy a rear kit like staangsfab or clayton and not look back.
i would weld a truss onto your rear axle that has the coil buckets incorporated into the design. i'm sure you can get what you need from TMR Customs.com

Get onto pirate?