I'm getting ready to replace the oil cooler and lines and install an Amsoil bypass system. I'm also installing an oil pressure gauge while everything is drained and apart. Where do I install the sending unit? Pics of location would be appreciated.

I would Tee in below the factory OP sender. Run the line out the back of the valley under the intake.

Had one heck of a brain fart when I typed the first post.

I should have said OIL TEMPERATURE SENDER.

I took an 1/8" pipe coupling, cut it in half and welded it to the oil pan beside the drain plug. Then I got the engine hot and drilled a hole through the pan letting the oil push the chips out hopefully. Worked for me anyway, not the best way, but I didn't want to pull the pan, to do it the perfect way.