Originally Posted by HexRei
Not sure where you're getting that number. GSP has traditionally had a reach of 74" according to the tale of the tape. There may be some times when the UFC got it wrong but for example I just rewatched UFC 56 and 74 and he was reported at 74" inch reach for each of those events. His arms do not look 76" long to me.
The tale of the tape's reach varies a lot from fight to fight, I've seen GSP with 74" a few times and 78" a couple of times. I've been following GSP close as he's my favourite fighter and most of the time, the TOT will say 76" for GSP. So I'm assuming he's around 76". That's amazing for a guy of his height but I guess he's got long arm and very broad shoulders.
A. Silva is 3.5" taller and has much longer arms, however I find him narrower than GSP (my opinion). That's why he only has a small reach advantage over him.
I've seen Silva with 77" or 77.5" sometimes. In his Leben fight TOT said 75.5" but that was his first fight in the UFC so they probably had this wrong. I'm assuming his around 77".
Conclusion: A. Silva will have 0.5" or at most 1" reach advantage on each arm, which can't be considered as "huge".
Here is an interesting image somebody posted before, you can see how much the reach varies from fight to fight: