[bluejudge]

Originally Posted by north

40 years ago, I wanted to open the hood tach on a GTO I had just bought, I took an old socket and ground down the exterior diameter till it could fit into there. Still have it in my toolbox.

Thanks North for the response. I didn’t see this until today. Yesterday I texted Randy Watson www.rctach.com and he was helpful texting me back with the correct size for socket which is 3/16 and yes it has to be ground down as North said.