I put my sensor in one of the "plugged holes" in the intake.........EZ-PZ
6sal6

6sally6, I'm running an Edelbrock Rpm air gap on the 351w and there are no other ports available on the intake.  I have a port at front driver side of intake but that's used for temp gauge.  I have a port on passenger side but that's for heater hose. Only other port is at back of intake for brake booster.

yeah I could change housings but most are made cheaply and everyone complains of leaks.  This one is a Ford Racing and gets good reviews.  Was hoping to not have to swap it out.
 

Is there room on the intake to add a bung? You can buy them from Summit or JEGS then have it welded in.

https://www.jegs.com/i/JEGS/555/15252/10002/-1

3/8 NPT is pretty large, any chance you could
go with a 1/4” NPT sender instead?

What is the wall thickness where you want to tap it?

Whatever you decide you need a round hole of the correct size.  I know this sounds dumb, but it is so easy to accidentally bell a hole oversize or end up with an oblong hole when drilling from an interrupted cut, using a handheld drill, improper clamping, poorly sharpened or poor quality drill etc.  Use a milling machine or drill press with proper workholding and quality tooling.

Don’t buy a poor quality tap. 

Get a good sharp HSS one.  Also consider NPTF instead of NPT.

Do not tap too deeply, I would only go as far as needed to get your sensor where you want it.  Try to use a fixture or a steady hand to keep from belling it.

Use good sealant.

Loctite 542 has treated me well.

Last edited by Bentworker (3/14/2019 8:54 PM)

Here is one more option for you.

Replace your manifold heater hose fitting with this something like this, remove the shutoff valve and put your sensor where the valve was.

https://www.amazon.com/MACs-Auto-Parts-32-50379-Heater/dp/B06ZY3ZR5P

1fststang wrote:

Only challenge there will be finding exact center and use smaller bit as a pilot.

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They make centering punches just for that. Should be able to pick up a set at a reasonable price.

I got my center punches at Harbor Freight.  Can't remember what I paid, but they were surely cheap, and have worked on many, many projects for probably over a decade at this point.  They come in very handy for even light fabrication work. 

Thanks BB, that may be the route I take using a file after I get it drilled close.

just need to find the tap locally now.

 

Glad your asked this question.  I was going to post the same thing.  I need a port for EFI temp and Gauge Temp.  Im adding a heater so I need one of them for Elbow for heater hose.   My temp sender hangs down a bit.  Will tapping our using a thermostat housing that is tapped going to interfere with actual thermostat?   Will the temperature reading be effected being its on the back side of thermostat? 

Last edited by Steve69 (3/15/2019 12:05 PM)

Much easier to drill and tap a new hole in the intake manifold.  That will also send the proper temperature to the sensor rather than being downstream of the tstat.
Sawa comment about pipe thread taps not being any different than straight thread taps.  BE CAREFUL WITH THAT!  The tapered tap, if tapped too deep, will allow the male pipe thread to go in too deep, sometimes to the point of falling all the way through the tapped hole!  So, don't tap anymore than just barely enough threads to get the male part to seal.  And deeper and you risk an oversized hole that will never seal.
I drilled and tapped my intake manifold behind the distributor to install an extra sensor, using 1/8" pipe threads.

Steve69 wrote:

MS wrote:

Much easier to drill and tap a new hole in the intake manifold.  That will also send the proper temperature to the sensor rather than being downstream of the tstat.
Sawa comment about pipe thread taps not being any different than straight thread taps.  BE CAREFUL WITH THAT!  The tapered tap, if tapped too deep, will allow the male pipe thread to go in too deep, sometimes to the point of falling all the way through the tapped hole!  So, don't tap anymore than just barely enough threads to get the male part to seal.  And deeper and you risk an oversized hole that will never seal.
I drilled and tapped my intake manifold behind the distributor to install an extra sensor, using 1/8" pipe threads.

Did you use one of these suckers?......https://www.youtube.com/watch?v=g3QpYCRAwSo
 

 
Those drill/taps Chuckee is using are not pipe taps. They are good for up to three holes before they break.

Useless bit of trivia: Chuckee lives just west and south of me. Not close enough to smell his goats or see his tractor graveyard.