Temperature gauge knowledge deficit

[dmjlambert]

Here is another thread I had bookmarked for good info about these senders.
http://67-72chevytrucks.com/vboard/s...d.php?t=779140

[chiefcfd]

Another thing, you are going to need to find the stock wire if it is still there. If not you will need to run a new wire to the stock plug if you are using the stock plug. It doesn't wire to the gage itself. It runs thru the printed circuit.

[K10-Kansas]

Originally Posted by chiefcfd

Another thing, you are going to need to find the stock wire if it is still there. If not you will need to run a new wire to the stock plug if you are using the stock plug. It doesn't wire to the gage itself. It runs thru the printed circuit.

Thanks. I'm in the middle of running the American Auto Wire Classic Update complete wiring harness to direct replacement for OEM dash cluster. I'm learning a lot today.

[K10-Kansas]

Originally Posted by dmjlambert

Here is another thread I had bookmarked for good info about these senders.
http://67-72chevytrucks.com/vboard/s...d.php?t=779140

Thanks, I went ahead and sent A1971Blazer a message.

I'm really confused by that NTP chart.

My engine has approximately a 3/4 inch standard female port. The 1/2 NTP is 25/32 female standard so maybe I don't need it machined to 3/8 NTP because 3/8 NTP is 5/8 standard female?

[Getter-Done]

Here is another article on NPT.
Hope this helps.
Link: https://www.pegasusautoracing.com/do...%203%2F8%20NPT.

Ordering and using NPT fittings can be confusing because the nominal sizes have no relation to thread size. To make matters worse, NPT fittings do not fit together the way most other fittings do. This has led many people to believe that they have mismatched sizes. Fortunately, NPT sizes are easy to identify. The sizes are also different enough that it is impossible to even start to assemble two different sizes together.


(Background)
NPT stands for National Pipe Tapered thread. It is also sometimes called National Pipe Thread, NPTF (F for Fuel), American Standard Taper, or simply "pipe". Most other plumbing fittings have straight or parallel threads, but NPT fittings have a tapered thread profile. The outside diameter of the male thread tapers down from the base, so the end of the fitting has a smaller OD than the base of the fitting. The matching female thread has a larger OD at the opening, tapering down as it goes in.

NPT fitting sizes refer to the nominal ID of a standard cast-iron pipe. This is where the confusion comes in. Most plumbing fittings are named for the thread size, but NPT sizes are not. An NPT fitting measuring 3/8" OD thread is actually a 1/8 NPT, not 3/8 NPT. Use the chart below to positively identify NPT fitting sizes.

[K10-Kansas]

Thanks Getter-Done. That explains why I'm totally confused on the sizes.

I went ahead and ordered this one https://www.lectriclimited.com/tempe...ng-unit-117353

Since my female port on the engine is 3/4 inch standard, do you think the unit I bought will still need to be machined?

[Getter-Done]

Originally Posted by K10-Kansas

Thanks Getter-Done. That explains why I'm totally confused on the sizes.

I went ahead and ordered this one https://www.lectriclimited.com/tempe...ng-unit-117353

Since my female port on the engine is 3/4 inch standard, do you think the unit I bought will still need to be machined?

If the female threads in your head are truly 3/4" NPT.
Sounds like you will need a 3/4" to 1/2 " reducer bushing.

As Accelo had mentioned above,
I am not a big fan of reducing bushing or adapters.
It's just one more place to have a leak in my eyes.

Sometimes that is the way to go though because of all the changes over the years that happen to these trucks.

I have pipe fittings in a big box in the shop.
I still have to go and double check on some sizes of this NPT stuff.