Thermostat Housing from YJ/TJ fits CJ7 4.2L, but...

[Josh85CJ7]

Hello!

I want to install a mechanical water temp gauge on my CJ7 AMC 258 i6 / 4.2l .

I have gone over every inch of the block & manifold, looking for an unused threaded port for the temperature probe, including the locations I've seen people suggest (here & elsewhere), and I just don't have one on my engine. I know from the previous owner that I've got a crate engine, but everything (up until now) has lined right up with what I've read about or seen on CJ7's with their original motors.

So, lacking a location to install the mechanical gauge's probe, I decided to follow advice I've seen various places, that you can use the thermostat housing from a YJ/TJ 4.0L, which has a threaded port for the probe. Ordered the housing, and sure enough, it has the correctly threaded opening for my mechanical temp gauge's probe.

The problem is that while the the YJ/TJ housing will technically fit on my engine, there is not nearly enough clearance between the threaded port and the nearest obstruction (a bracket for the fanbelt pulley). I'd say there's a 1/2" or less room for the probe's threaded collar to stick out. Which is much less than is needed.

I'm including 3 pics below, to illustrate the lack of room.

My question: Is there a different YJ/TJ housing I should be using, with a port coming out at a different angle? Or is there a mechanical temp gauge on the market with an extremely short probe and low profile threaded collar, that would actually fit on the TJ/YJ housing I have, without running into the fanbelt pulley's bracket?

The mechanical gauge I'm trying to use is just a $25 gauge from Napa Auto Parts. Nothing special, but I can't imagine any temperature gauge's probe being low profile enough to fit in this space.

 

[gutthans]

If you go to Auto Service | Car Engine Service | Alabama | Hesco and look at the HFTH-4 you will see what you need to do to your housing. You DO NOT NEED to buy the HESCO unit, simply tap and thread the flat (on yours) that points towards the radiator.

Buy a threaded plug for the hole you already have.

Oh, and remember to use thread sealer when you install so you don't strip out the aluminum!

 

[Lumpy Grits]

Josh-PLEASE move that fuel filter.
That is the source of many engine fires, where it is now.
They start leak'n and drip fuel onto the hot manifolds-----
LG

 

[Dan77CJ7]

hi josh my probe is on the passenger side of the block, i like the ides of the new housing, here is some pics of mine and some other spots that i had thought about using when i upgraded my intake, i didnt plumb the intake tho.