I have a Sunpro mechanical temp gauge. I'm trying to figure out what kind of bushing (or adapter) I need in order to install into my 383? Here's a pic of the NPT bushing I bought today. Realized when I got home that it's not what I need. The probe doesn't pass through it, but even if it did how would the probe seal tight? Just confused, so can someone point me the way to what I need to get?