So I made a fun build, but does it work? (Grappler/Rager/Bear/Psionic)

[Town_Drunk]

So I made a character, a city brawler who when he rages turns into a bear, and specializes in wrestling.(?) He has a multitude of grapple feats, and many cheesy chunky ways of buffing himself to be very cheesy. His levels are Barbarian 6/Psionic Warrior 2/Fighter 2/Bear Warrior 10. This is how the ultimate grappler is established, which if all the math is right, gives him +75 to grapple checks. But a quick question. I know I can't cast Psionics during my rage, but what about *before*? I cast Expansion to make myself Huge Sized (Because 6 more points spent say so), then I rage, casting polymorph onto myself, becoming a Gargantuan Dire Bear. While my damage is s***, I can keep an Ancient Red Dragon grounded with ease as my team mates hack it to pieces. And I am on par with a Tarrasque with it's Grapple of +81. And to think, with one more level, with Legendary Wrestler, and +1 BAB for an additional level in Barbarian, I get +86 to Grapple. Now, just to clarify, I get Improved Grapple (+4), JotunBrud (which cancels out as soon as I'm large size), Bear Totem (+4 to grapple when raging), Flexible Limbs (+2), Gargantuan (+12), Absurd Str mod of 22, Gloves of Titans Grip (+8, bear might cancel it out, so take original and subract 8 if so), Iron Grip (+4 Psionic Enhancement) makes a whopping +75 to grapple with my 19 BAB. Would my transforming into a Bear make me a Large Bear, or Gargantuan bear?

[Kaje]

I think you would only be a large bear, but that you would still have the ridiculous strength bonus from expansion+bearshape.

[Town_Drunk]

Forgot to Add, the short run is that this is his full grapple string.
30 Misc+22 Str Mod+19 BAB= 75
Without the Titan's Grip: 67
Without Belt of Giant's Strength: 64

When he's Huge Sized, he gets
+26 Misc+13 Str+19 BAB= 58

[Town_Drunk]

But expansion increases my size by 2 size categories, so would that not make it so it stacks with my Large sized bear form, making me Gargantuan?