Is there a big advantage to change my 6speed tranny to 5speed in stock turbo setup?

As I have seen 10sec stock turbo evos have trap speed around 125mph.
The 4th gear of 6speed at 8000rpm has around 122mph so why to change my gearbox?

 

Well for one, a lot of people will tell you the 6 speed is not as strong as the 5 speed, can't handle as much Tq, and no one really does anything to build them. I have a 6 speed love it, and will never go with a 5 speed.
MIKE

 

TRE builds the 6 speeds

 

I am talking about stock turbo..
I don't think that I will destroy 6speed tranny with stock turbo setup...

And as about the gearing it has 122mph at 8000rpm so why everyone change it to 5speed?

 

5 speed has a longer first, and better final drive for drag. I have a 6 speed and 5 speed evo(both ixs). For a daily, the 6 speed feels better. First through third gears are the same thickness on both gear boxes. The six speed gets hot so cool it down between runs. Hope this helps.

 

Horsepower does zero damage to a transmission. You could have 1000WHP and it would be fine. It's the torque that breaks things. Stock turbos make a LOT of torque and quick, like 400 FP's at 4000 RPM to the wheels on meth That said keep your six speed, I love mine as well.