You can buy the K-frame kit from firm feel, that is what I did along with the LCA reinforcement. Just weld up all the seams and any places that look like they need it.
Funny, I paid like $48 for a quart of Por-15 semi gloss from my paint supplier and looked up a link to post for you guys and found a great kit for cheap.
Amazon.com: SUPER STARTER KIT BLACK SEMI-GLOSS: Automotive
Probably enough to do a rear diff or a k-frame.
