I got a truck egine out of a suburban and threw it in my camaro, everything is great except I have this one problem... The oil pressure sending unit hole was pluged so I took out the plug and put in the sending unit, It looked like the hole a little farther up and to the rear of the engine was the hole used for the truck sending unit, I tried to switch the plug to that hole but the plug is too big, so I went and bought a plug the size of the sending unit for the truck... turns out it is the same size as the one I took out. It is really hard to see the hole but I have tried lots of different thread sizes and cant find the right size, any sugestions?

 

If my guess is correct, it should be a 1/8-27 NPT (pipe taper) thread.