Temp gauge
 

On rare occasions my temp and gas gauge go out on my 87, I was wanting to install a backup temp gauge, could I have two temp gauges on one engine?

No reason why not that I can see.
Would you use an existing sensor, or add a new sensor somewhere in the water jacket? I'm pretty sure that if you want to use an existing sensor, you would have to disconnect the original temp gauge, because two gauges in parallel, or series, either one, would change the current reaching either gauge enough to alter the sensor's output rather severely. Which, of course, would result in an incorrect value on the gauges.

Either way, if you want a separate temp gauge, you can either use an existing sensor, but disconnect the original temp gauge, OR you can add a new sensor to go with the new temp gauge, to allow both gages to function at the same time. Probably your best choice, as the newer, separate, gauges have a sensor included, calibrated to match the gauge, and vice versa. The gauge is designed to match up with the sensor included with it.

Really, though, you should troubleshoot the intermittent wiring to the temp and fuel gauge. You've got a bad wire, solder joint, or connection, someplace. From the description, either IN, or feeding, the gauge cluster. Most likely a loose or broken connector to it, but it may be further away than that. Maybe a broken ground wire, or run on the gauge cluster's circuit board. Intermittent problems are the most difficult to find. I would examine the gauge cluster's circuit runs with a magnifying glass, very closely. Wiggle the plug feeding it, too, to see if it's the problem. That's just me, though. I was a radar technician my entire working career, though.

Does this help at all?
Pat☺

Yes that is helpful, thanks Pat, I was thinking to install another temp gauge, maybe kinda lame but seems like an easy solution, next question; If I am going to leave the existing gauge is there a way to hook up another without a big ordeal?

Oh, certainly. Usually, "aftermarket" add-on gauges come not only with their own sensor, but the wiring, and directions on how-to install them. The sensor may fit a threaded hole you already have in the water jacket, if it's not in use, or may come with directions on how to drill and thread a hole to install the sensor in the location you desire.
Some also will install into the fins of the radiator. On the outside, so you don't need to intrude into the water jacket. Or something similar.

It's important, nay vital, critical even, that if you drill and tap into the water jacket, you make absolutely certain that you catch and remove every little bit of waste metal. It only takes a very small piece of something to block a water channel in the block or head. That can cause a hot-spot, which can cause you all kinds or trouble. If you're going the drill/tap route, do it someplace easy to get to the inside of. Something removeable is the best choice. Something like the 90° where the thermostat sits. That way, you can be completely certain you wash out all the little bits of metal, before you reinstall it.
There IS a drain plug in the block, near the back on the driver's side, I think, about 1/2 way down, that you may be able to use, without any drilling or tapping, but I won't swear to it. If you do use it, though, make sure that if you pull the sensor to drain the water system, you clean the sensor head and threads thoroughly, once you have removed it. Make sure that it is safe, as well, before you use Teflon tape to help seal the sensor in the threads. That's a common thing to do, but may not be advisable in this case. It may need a good metal-to-metal connection of the sensor to complete the entire gauge's circuit. Teflon tape will block that connection. Read the instruction on the gauge to be sure.

Maybe someone who's done this kind of thing can chime in with some advice. I hope so :D
Good luck to you!
Pat☺

https://cimg3.ibsrv.net/gimg/www.yot...cf4d1aaf6.jpeg
Thanks, is this the elbow above the thermostat that you are referring to?

https://cimg8.ibsrv.net/gimg/www.yot...33fe38d68.jpeg
To clarify

Yes, that's the critter :)

Easy to get to, just pull up the air cleaner, and 2, 12 MM headed bolts. Pull the hose off, and voila, you have a metal tube you can drill and tap, then wash thoroughly, without any chance of getting metal bits down into the water system. You only need to drain a quart or two out of the radiator to get the water level in the system down below the elbow, so you can remove it without making a mess, and losing that much water.

By the by, the bulge I see in the hose is an indicator that you NEED to replace that hose, at the very least. SOON! I would replace all 3 hoses, if it were me. If the one you showed is that bad off, I'd wager they are all that bad, and need replacement. Not that difficult an evolution, although you do need to drain as much water out of the system as you can. No matter how much you drain, however, be ready to get a little water down your arm when you pull the bottom most radiator hose. Happens to me every time. Wear safety glasses under there, too. That stuff burns when it gets in your eyes, believe me. Since I only have one eye left, I am very careful with it :D
You may need to cut the old hoses to get them off. If you do, cut straight along the direction the hose slides onto the metal it joins. That will let the hose split, and you can peel it off.
Save the water you drain, and if it's clean enough, you can pour it right back in when you get done. Looking at that hose, though, I'd wager the water is not re-usable. I always pour water, whether new or used, through a nylon stocking, stretched over the funnel. It makes certain nothing can get into the system as you pour. Nylons are cheap as heck, although you may get some odd looks when you buy them :D :D
Keep an eye on any water/coolant mix you drain out. Dogs and cats, if there are any around, will try to drink it, and it WILL kill them, slowly and painfully. Even in very small amounts. Discard properly. Keep it away from animals!

Finally, while you've got that elbow off, pull out the thermostat and test it. Put it into a pot of water, and bring it to a boil, slowly, Have a thermometer in the water to see the temperature. It should pop open at 180° F. If you have one of the newer, 2 stage thermostats, I can't recall at what temp the small one opens, but I believe the main should open at 195° F. You an get a thermometer that will read temperatures that high at Harbor Freight for about $5.00, I think.
When you put the thermostat back in, check the rubber o-ring on it for damage, cracking, and so on. They cost about $1.50 at Rock Auto. I, personally, rub a thin layer of Vaseline on the o-ring. It helps preserve them, and makes them last a lot longer. Finally, check the space where the o-ring sits when the thermostat is in. It can be prone to corrosion, and you may need to clean it out, before re-installing the thermostat. The Vaseline will help the o-ring seal better, too.
I don't know for certain if it makes a difference, but I always place the thermostat in such a way as to have the little "jiggler" valve at the back, IE: toword the curve of the elbow. On my trucks, that's towords the firewall.

Good luck! I know it all sounds like a pain, but better to do all this at once, than to blow a hose on the freeway, or overheat on a long drive. And those hoses are not long for this world, you can see clearly.
Pat☺

Thanks 2toy, sorry I took so long to respond, so yeah I will see about replacing the hoses, I just replaced the thermostat and water about 100 miles ago and I will look into running a parallel temp gauge.
Yeah The temp/ gas gauge work 98% of the time, just a little more concerned about it, after I rebuilt the carb it starts to over heat on this one hill I drive a lot, so anyway it's easier to throw a band aid on it until I get my shop roof up, then I can really dig into my repairs
If anyone has any recommendations for a decent after market temp gauge shoot it this way