add to 6inch kit

[xlredtruck99]

I have an 04 6.0 with a 6in superlife kit. I would like to go to 8in but dont want to have to buy a whole new kit. Can i just add blocks and/or add a leaf kit to it?

[Betaracer]

rear is easy. increase the block size 2" more than what's there (don't stack).

Depends on how the 6" was attained on the front. If you have 6" springs, then a 2" hanger kit can replace the OEM setup. Hanger kits are available from different manufacturers in 2" (sky manufacturing), 3" (icon), 3.5" (fabtech) and 4.5" (icon).

Depending on what length shocks you have, those may need replacing.

[CT Performance, Inc.]

You also may end up needing DS mods..