4.2.1.. downgrade to?

[Gunnz3gs]

I know theres probably a thread on this already so sorry for the repost, i just need a quick solution. Im on 4.2.1 jailbroken and unlocked, i keep having the drained battery issue even after i used "sam". So i want to downgrade to any version under 4.2.1. Yes my SHSH is saved on every iOS4 version. Just dont which one to go to and how. Custom ipsw? What jailbreak software? Sorry again for the repost. Thanks Ahead.

[Simon]

You can use this for help with downgrading: http://modmyi.com/forums/general/725...e-restore.html