aux trans cooler
 

does anyone know what size bolts i need to install the cooler?i know theres four!

aux trans cooler
 

do anyone have the factory one installed from the factory...rockauto offers many different ones.but the one that i bought that says factory installed doesnt seem to fit properly....???

If you’re intent on a factory cooler, getting it from GM (dealership or a GM specific website) is probably your best chance for sourcing one.

I don’t know for sure what size bolts they are but they’re likely M6 or M8 - if you can get one out, most hardware stores have a bolt size and thread pitch gauge to match them.