Will a Stock 489 handle 700hp?

I have about a 650hp 408 H.P. that has a H.P. 727 behind it 2,500 stall. It is time to put a diff in. Some people are telling me a stock 489 8.75, with stock gears, race axles, stock pinion yoke, stock bearings, etc, will handle 700hp with an Automatic Trans.

Some people are telling me I need this pumpkin for it:

Mopar 8 3/4" (8.75) 489 Case Third Member

I want the green bearings, a 3:23 ratio, 6 Helical Gear Sure Track II, w/a 1350 Yoke.

Problem is I can get a stock pumpkin for $850, while the race pumpkin with the above features is $1,425. Don't get me wrong, I am not out to pinch penny. What I don't want to do is spend the money on a race pumpkin when a stock one will do. If the stock will not do, I will definitely buy the race pumpkin. No Problemo! I have heard a lot of different answers.

Members who have experimented in this area will prove most helpful. I need to know what your experience was.

I'm upgrading to a Ford 9 inch so I'll be selling the S60 out of my Duster. If you have tubs then this might be something to think about. It is 50 inches wide from hat to hat.
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