interceptor_1972

The bolt on version allows you the flexibility to change the perch angle should you change lifts in the future. If you don't foresee changing a lift or going to a bigger lift down the line, cut the old ones off and weld new ones on. The Teraflex weld-on perch comes with spring retainers. Or they're available separately as well - here's the one Northridge has. A few other brands are also available.

mkjeep

The Rockrawler wedges fixed em on my tera 4in. Easy fix.

renpia

Do a search for Spring Retainers. There are a few manufacturer's for rears. I only found one available for the front when I was looking for them last year. I forget the brand I bought, sorry. Do a search, I'm sure it will come up or there may be more options available by now.

rinkishJK

I run the rk wedges. They definitely help ALOT with the spring bow. The only way to get the springs "perfect" is with new perches like the ones jks and teraflex make. But for $25 u can't beat the rk wedges!!!!

Jks also makes rear lower retainers. Currie makes upper and lower but more $$, and u can't run a spacer with them if u needed to for weight/sag.