Can I upgrade to 4.2.1 using TU?

[movievision]

Hi all,

I know I'm seriously late to this whole jailbreaking thing... I am running a JB'ed ipad on 3.2.2 and have never updated it, but have blobs for 4.2.1/4.2b3, is there a way I can update it to 4.2.1 using tinyumbrella and jailbreak? If so, how?

Thanks!