Water jacket port location?

Need some advise on where the best location would be to mount the coolent sensor. The instructions for my fast fuel injection says in the intake manifold , but clearly my 258 straight six has no water running through the intake...before I tap a 1/2" hole in my thermostat housing does anyone have ideas for a better location...does my cylinder head even have a threaded port somewhere?

 

The later 258s with an aluminum intake do have coolant running through the intake manifold. IIRC the manifold sports a double CTO tapped into the coolant passage.

The earlier engines with an iron intake use holes in the side of the block for CTOs (driver's side, mid-way down) which you could take over.

The gauge sender is up by the thermostat housing, in the cylinder head. You could take over that location.

Actually tapping a hole in the water outlet does not seem like a bad idea. This part has a prominent place for a tapped hole -



It's probably 1/4" NPT.

 

Drilled and tapped my housing ...here are some pics....notice the made in China stamp.... Boy I hate that!!!!

 

I'm impressed by all of the laser stuff, I'm old school, drill a hole, hope it's sort of square to the surface.
I hope there's still enough clearance in the housing for the thermostat.

 

Good work.

There's a lot of machining you can do with a drill press. It's on my list.

I was thinking about the existing flat spot, but that sender may be too big for there, and would have blocked the passage.

Interesting ... CHINA!

 

Looks great. That "CHINA" sure is prominent. Maybe you could fill it with some JB and paint over it if it bothers you?

 

Yeah, probably made in China (but so was my wonderful jeep loving wife!) but you can replace your 258 t-housing with that from a 4.0 and it has a 3/8 npt hole all tapped and ready to go. I have one on my 258, works great!

 

Thermostat housing is pretty close to the fan blades ....sensor is mounted , safe and clear of the fan blades....