Technical sbc fenton 3 duece question

Hey all! Hope the winter builds are chugging along! I have a fenton intake I picked up years ago. Just dug it back out and noticed that one hole has some threads that need attention. It appears to be for a water fitting or maybe a thermostat? Any help would be great. So I can find the correct tap. It’s pretty buggered. Might end up welding it and remachining the hole.

 

pipe thread-see if a pipe tap cleans it up(gently) enough to seal w/ a PLASTIC sched 80 plug -plenty of tef tape

 

You need to bead blast that off to know what you have. Aluminum corrosion can be deep.

 

Don’t think they came drilled there, it was a undrilled boss so if you’re using a tap I’d measure it carefully in case Bubba has been there. It’s for a crossover. If you’re not going to use it I’d get it welded up.

 

Well it appears it was cast in there since the bottom has a bit of a floor. Looks like counter bored and tapped. Anyone know what it could have been for?

 

It looks like it could have been used for a temp sending unit, in which case it SHOULD be 1/2” NPT.
Like previously suggested clean it well and carefully try a tap.

 

That is where the temp sender was installed in 1955 Chevy 265 engines. There is probably a flat spot behind the #4 intake runner for the oil return for the front mounted oil filter canister. This is an early intake.

 

heater hose, temp gauge, would be most common. Just chase the threads with a pipe tap. if they don't clean up step it up a size and cut new threads. You can either use it or plug it.

 

Something added...as said. Here's one I have:

 

You can drill it out, tap it, and use a M/F threaded NPT bushing to get back to 1/2"NPT.

 

Thanks, I have drilled and retapped to 1/2” not then plugged. Good to go now!