installing aftermarket mechanical temp. sender on 318

[Megunticook]

As long as I'm adding an oil pressure gauge, I figured I do the same with water temp.

However: it appears that the hole tapped in the block where the water temp. sender screws in is 1/8" NPT. But it doesn't look like the sending unit for the new gauge will fit--the metal "bulb" that sits down in the coolant appears to be slightly larger in diameter than 1/8."

There is some sort of threaded plug adjacent to the temp. sending unit, the plug has a square hole in the top rather than a hex cap. This plug has a larger diameter--can I remove that and thread the new sending unit in there? Or am I missing something?

I would take some pictures but my wife is away with the digital camera.

Maybe somebody else with a 318 who's installed one of these mechanical-type sending units can tell me how they did it. I remember doing this on a slant six of mine seventeen years ago, but I can't remember exactly how I did it.

Thanks!

[Speed Dragon]

I know what you mean, I looked at that on mine, cause I have a white-faced temp gauge I'd like to use. I think the adjacent plug goes into the runner though, not the coolant passage. Only way I saw to make it work was to find some sort of adapter that would screw in there. Even if the sender would fit through the hole, I think it's too long and would bottom out before you could screw the fitting in. You might could drill it out to a larger size, re-tap and install a deep fitting to put it in.

[bherder]

Heh .... I remember running into this prob 35 years ago....

You can do one of a few things... Because basically what you've got to deal with is, an 1/8" pipe thread hole.... And most popular gauge kits don't deal with this, because it ISN'T a Furd or Chebby...

Switch over to electrical sending unit gauges (Which gives you much more versitility)

Aftermarket intake (Like an Edelbrock) that gives you all the options you could want....

As Speed says, drill and tap the existing hole....

Live with what ya got. If it ain't broke, don't fix it, I always say.... :D :D :D

[Megunticook]

OK, I guess I should've just bought the oil pressure gauge as a standalone. Oh well, I can always just leave the temp. gauge dead seeing as how the stock gauge works fine.

I know I installed a Sunpro mechanical water temp. gauge on my slant-6 years ago after the stock gauge went out. Wish I could remember how I did that...

[bherder]

Don't the /6's have the sending unit in the water neck/thermostat housing?
It's been a looong time since I've had one, so I really don't remember...
If that were the case, it'd be easy to adapt...