Coolant Overflow Reservoir sensor
 

Do the tanks have a built in sensor? I read that the sensor is built into the tank. Mine has a short and the tank has a crack, but does not yet leak, so I was going to replace the tank, but don't know if the sensor comes with it. You cant appear to just buy the sensor.

Indeed, the sensor is available only with the tank.
I would not wait for the tank to start leaking. Boiling hot liquid at 16 PSI coming at you is no fun, and if the tank shatters on the highway, you'll end up with a messy overheated Satty, and no one wants one of those.

If you can ID the brand, see if you can find a replacement petcock for your radiator. If not, replace the tank and radiator at the same time.

Now is a really good time, with the crack, n all......

crack kills

Just Say No.

But seriously, thats the plan. And all right good to know. The pentcock itself is fine, its the plastic around it that is physically apart of the radiator. I mean with 260k miles it wouldnt hurt to have a new radiator Im guessing. But the coolant is ugly af so Im going to flush her good and put the green stuff in. I don't trust DEXCOOL.

265 K n my 97 SC2 running only dexcool, 1st radiator lasted over 200K.
Just do it.

It costssss more and I can always change back. Plus with how much I need to flush it wouldnt it be cheaper to run the green stuff for a while, get the krud out(garden hose cant get everything), then once its a relatively clean system switch to the proper mixture of DEXCOOL?

Sometimes knocking stuff loose in the cooling system can do more harm than good. If it gets knocked loose during the flush, it may travel through part of the system and lodge elsewhere, blocking radiator passages or cooling passages in the block. Also, sediment that has found a place to rest can get back into circulation and plug up the system worse than it is.

I never actually do a flush per se, I drain the radiator and the block and refill. Especially with that many miles on the engine. Sometimes less is more.
But that's just me. Haven't gotten bit by it yet.

I know what you're saying. But you are WRONG(joking) I am purchasing a dorman tank and a ACDELCO cap, I heard bad reviews of the cap that comes with the dorman tank.

As you wish.

Nothing wrong with the Dorman caps. in the ones I bought a few years back.
This from a guy who avoids Dorman anything at all costs.

Seems to be a mix bag of "it fails rightaway" and "it works" with those caps. Poor quality control maybe. Same with felpro gaskets for the valve covers... seems half people get ones wayyy too long and then go buy another(in our case basically option between Mahle and Felpro at stores. Maybe more online) and it works... I got that. The second one was actually too long but it was short enough I was able to aggressively shove it tight every inch around and just got it to fit, and boy I had to push to get it to fit.

I too recently got a FelPro that was too long by about 4 inches.

Bought an AC Delco and fit right in there

Oh, if you want zero ignition issues, run the stock copper NGK 5643's {#BKR5ESA11]
If you get P0341's after your new coil, don't say I never told you so