Ok, my old phone, was 3.1.3 from factory, then I Spirit jailbroke it... then i got curious and did the 4.0 upgrade... (stupid i know) and after a month i did the jailbreakme.com jailbreak.. now today i returned my phone into apple for cosmetic cracks and got a new replacement for free.
the new replacement is directly from apple, Never before jailbroken NO SHSH blobs, 4.0.2, and MB (Not MC) and i did the DFU mode check to see the 393.3 or whatever it is, not the .3.2 just to confirm it is the old bootrom.
Now, I have a 3gs, 4.0.2, with the old bootrom.
What software should I use to JB it?
I also ran Forecast on it, and it said it is Unlockable aswell, which is nice.
You wont be able to jailbreak it right now. Even though you have an old bootrom, you would still have to downgrade in order to jailbreak. Without shsh's downgrading isn't possible. Have you used tiny umbrella to double check that the phone does not have shsh's on file with cydia?
I just downloaded tiny umbrella, and i submitted my 4.0.2 SHSH to cydia's server.
but it successfully submitted 4.1 SHSH? Im not sure how that is possible, since im not on that firmware.. but anyways, when I clicked on Check SHSH's, it only shows 3GS 4.1, nothing else.
It saved 4.1 shsh's because that's all that apple is signing right now. No matter what firmware you are on you will only be able to save shsh's for what's currently being signed.