I could make more of the front spring hanger boxes but there are several folks who already make them so it doesn't seem like a big winner for me to make them too. US Car Tool has some heavy duty spring hanger boxes and so do some other places.

The ones I made for my car were out of 0.188 steel so they are really stout. Probably thicker than they should be since the frame rail is a lot thinner than that. If I was going to make more of them I'd drop it down to 10 ga or maybe even 12 gauge so they would weld to the frame rail easier.