What thread size is this plug??? (1 Viewer)

[love2fly]

Hi, anyone confirm that the intake manifold plug on a 1980 FJ40 is a 16mm fine thread size.
Planning to install a vacuum gauge and need a screw in hose barb or adapter.
Thanks much

 

[Fast Eddy]

Your picture looks to me like the plug in the head that replaces the air injector ports.

 

[love2fly]

No its the plug from the side of the intake manifold for accessories. It does look like one.
Thanks

 

[sggoat]

I have 3 different sizes of BSPT brass barbs-I'll check to see the overall size at the tip of the threads--
here they are---
The plug that came out of my 77 oem manifold is shown in the last pic-along with the third BSPT barb

 

[love2fly]

The plug is around 5/8 or 16mm but I will mic it later to give you a better idea. Kind of thought that there may be a few different sizes.
That out of the 77 plug looks to be a bolt type. Hum- Went to a hardware store to use the thread seizer they have and on the metric side it was close to 16mm but would not screw in the fine or cores thread size.
Checked the non metric and close to 5/8" but would not fit either thread type also??

Big thanks

 

[sggoat]

my metric thread gauge shows 1.0
The plug diameter shows 9.97 mm at the head end, and 9.71 at the tip---BSPT

 

[love2fly]

Sggoat, got a chance to check the size and pretty much got 16.44mm +- 2 on the .44

 

[love2fly]

Tried two more brass hose barbs and both are not correct. The 16.45mm does that work on your manifold?