Try googling pwnage or redsn0w and 4.3 jailbreak, I've already found a few hits, but you might want to go ahead and do 4.3.1. I've had it on my iPhone until 4.3.1 jailbreak came out and I updated and jb 4.3.1 no problems no issues.
Just follow the iClarified instructions to the letter and you shouldn't have issues.