I have a 4.2 triple SU intake manifold I’m trying to use on my 68 FHC. The water inlet on the back of the manifold has a steel fitting that screws into it. The threads are stripped on the aluminum manifold and my machinist can’t figure out the threads on the fitting. He says it’s not any of the usual suspects. SAE metric, etc. Does anyone know what this thread is? Even better does anyone have an idea on how to fix this?
I was hoping for a helicoil or something similar but not being able to identify the thread is making it impossible
Thanks for any suggestions