I assume by 350t you mean 350 ft-lbs of torque?
If done correctly a 7.5" can handle more than that.....
I'm told mine will take over 500 in it's current form. The locking unit is rated for 800....
Then again I see you were talking about the 7.8.....![]()
As said before a similarly built up 8.8 will be stronger than a 7.5 barring some part defect.