? Correct Reducer for 1" Half Coupling Element

I'm planning on silver soldering my element connection, and have built a keg tool in the past. My question is what size reducer should I order for my 1" coupling.

I read a few post that used 1" x 1.5" but it was mentioned it was way to big and only needed pulled like half way. I'm pulling through a bayou classic so being thin I don't want to over shoot. Does anyone else have a recommendation. I will be using the harbor freight punches to make the hole.

Squeeky

every coupler and coupling is different. when i pull dimples i go a couple of turns at a time. if you overshoot slightly, you can hit it with a block of wood and a hammer to knock the ID back in a little.