Can anyone give me info on a 8.8 GT solid axle swap for my 99' cobra? Except for the exaust,  is this a direct bolt in for a cobra? HALFSHAFTS VS. SOLID AXLE. The IRS looks like a nightmare to work on! I want to get 375 to 400 hp out of this car N/A and have have been told by many that the half shafts are the weak link.

The half shafts are the weak link but there's axles you could get for it that can handle up to 600hp now.  If you want to swap, yes a GT rear will swap right in.  If you're interested in the half shafts, I could find out who makes them.   

Oh yeah, I found a few companies (GKN) that make high performance halfshafts but they are way out of my $ range , we're talkin $1100-1300. They would handle all the power Icould throw at them but its still a alot of money. A used 8.8 goes for what? $700-800. Also what ratio does a GT 8.8 come with, cobra is a 3.27 if i'm not mistaken.  

the axle swap is way more complicated then rear for rear.youll need upper and lower control arms,brake bracketry,abs sensors,plus many other little goodies,save yourself the money and get some good half shafts.i was just looking into a solid axle for my cobra,and with a properly built rear your somewhere over 2 grand.your best bet if your hellbent on solid axle is somebody with a solid axle car that wants to swap,and park next to each other,and get to swappin!good luck!  

He's right about the cost and if you can find one that wants to swap, that would be the best scenario.  A rear could be found for as little as $200 but that's used and you'd want to rebuild it since you don't know the abuse it's had.  After all is done, it would get a little expensive.  If you could wait and get the shafts, that would be a lot less trouble to do.