This is what I did. welded a 1/2 " nut over top of the rounded off head. Get a way better bite on a larger nut.

 

Tranny pan drain bolt is a pain. I removed my first one with one of these: http://www.sears.com/shc/s/p_10153_12605_00952166000P

I bought a new bolt to put back in. You cannot/should not tighten that bolt too much. I just snug it past finger tight.

 

ive got a huge nut welded up on mine i think it was a 3/4 inch but i wont have the problem now that my 65e is long gone.

 

Those work awesome, Ive had great luck with those too.

 

I've got several out. Oddly enough I've had more luck on 01-02 then i have with 03+

 

The two methods above are what I have done in the past. Personally I think Gm was smoking crack when they designed that plug. Why not put something in there that you could actually grab onto!

 

Vince Ive used the same methods also. For some reason the 65E in my truck doesnt have a drain bolt though? Vince would you know why that is? Its just an 05 VHO LQ9 truck with a 65E and a 14 bolt rear.

 

They stop making them in 04 I believe. It really was a shitty design IMO.

 

I figured it was something along those lines. And yea it was a shitty design. Im sure GM technicians have a list of engineers whose asses will be kicked for those types of shitty designs if theyre ever caught in public. I know at the Honda shop I work at weve got a running list a mile long of people we will beat senseless for those kind of designs.