These days I wouldn't be surprised if they are all made on the same line somewhere in China. It might be the price difference is in the cost of the boxes they get tossed into.

 

GM original is higher quality than Delco (assuming its 'Gold' or 'Professional'). I bought Moog stuff for ever but have recently switched back to GM unless it's a Moog Problem Solver that, well, solves a problem. Good example is the GM pitman arms Moog has with a dual trapezoidal bearing vs a spherical one.....solves death wobble on some stuff like GM vans.

GM OE stuff has a better chance of being made in North America as it's sourced from whoever makes the stuff going to the assembly lines. Delco rotors... Chinese, GM OE rotors....USA.

 

I've always done MOOG (Just used on a 2010 rebuild last year) for the front, and a member on here cited some issues that MOOG quality has gone down. So far so good on mine but admittedly only 10k or so miles on them.

 

Moog isn’t bad, they had a bit of a rough patch when they ramped up operations in Asia but they seemed to have gotten their QC under control.