ChadMarkley,   Have you tried the process of downloading the update and then running it to extract the files, once extracted locate the firmimg.d8 file and then use that file in the Update tab of the iDrac?   Let us know.      
I have an R630 running the 2.70.70.70 iDRAC firmware. I've tried every version of update newer than what is installed and I consistently get the error, "Unable to extract payloads from Update Package". I have googled this to death and I can't seem to find a fix for this. I am attempting the update via the iDRAC web GUI. Would love any suggestions!
Unable to upgrade idrac8 from 2.70.70.70