Installing Mechanical Water Temp Gauge

[Clarke]

Since we're taking longer and longer trips in our GMC hauling the camper, I've decided to install a couple of mechanical gauges, just in case the electric ones fail me.

I did this years ago on my inline six and I felt better having them.

I attached a picture of the driverside of my 305D block... Notice the pipe plug in the lower righthand side of the photo... I'm assuming this is where I install the sensor for the mechanical water temp gauge? I notice there is one on the other side too, but with the starter and the exhaust flap thing, it's kind of crowded on the passengerside.

[AZKen]

Not sure the probe will fit, may hit back wall. That plug is a drain I believe. I don't think a backup mechanical gauge is necessary. If you must have one, it should be near the electric one on the front water crossover manifold. A Chevy thermostat housing (water outlet) with a pipe threaded off-set hole is available. May have to enlarge one mounting hole to fit V6 pattern, not sure V6 T-stat fits this housing but try Murray 84842 type..... Or you can drill and pipe tap into the crossover manifold, front of manifold, driver side (large flat area). Mount probe horizontal so as to clear T-stat. Either way will keep the two senders (switches) near each other for accurate comparison.

[Clarke]

Originally Posted by AZKen

Not sure the probe will fit, may hit back wall. That plug is a drain I believe. I don't think a backup mechanical gauge is necessary. If you must have one, it should be near the electric one on the front water crossover manifold. A Chevy thermostat housing (water outlet) with a pipe threaded off-set hole is available. May have to enlarge one mounting hole to fit V6 pattern, not sure V6 T-stat fits this housing but try Murray 84842 type..... Or you can drill and pipe tap into the crossover manifold, front of manifold, driver side (large flat area). Mount probe horizontal so as to clear T-stat. Either way will keep the two senders (switches) near each other for accurate comparison.

Yeah, that's a little more drama than what I want to deal with. I'm not into drilling and tapping cast parts. I'm afraid the existing pipe plugs in the block (drains, as you call them) are most likely too small diameter for any probe connection that I have seen in the past, and like you said, hole may be too shallow for a probe.

Well hey, if nothing else, I now know that I have a couple more options where I can drain the coolant without removing the lower radiator hose.

Thanks AZKen,

Clarke

[bigblockv6]

Another possibility would be to install a sending unit on one of the block off plates on the block side of the cylinder head preferably the passenger side. Take the plate off, drill it out and weld a bung on it for the sending unit.

[Clarke]

Originally Posted by bigblockv6

Another possibility would be to install a sending unit on one of the block off plates on the block side of the cylinder head preferably the passenger side. Take the plate off, drill it out and weld a bung on it for the sending unit.

Hummm... I think you're onto something there. It would be consealed by my oil-bath aircleaner housing too.

[Funky61]

My truck had one on the front crossover thermostat housing, next to the hose; but the blocking plate sounds like a great idea.

[Clarke]

Several weeks ago I completed installation of Retro SunPro vacuum, water temp and oil pressure gauges.

I installed the water temp sender on the left-hand side of the block (drain plug), then I moved the existing oil pressure sensor over to the other existing hole on the top of the oil filter housing and installed the oil pressure sender where the oil pressure sensor was (see attached photos).

According to my new gauges, the water temp is 175-180 degrees and the oil pressure is 58-60 psi. The vacuum is 20 psi.

Last weekend I towed my camper approx 3 hours to a camp ground/lake and a buddy of mine towed my JEEP, for a long weekend break. I fished one day and went four wheeling on the other day. I was proud of the truck; it did a good job. Having the extra gauges gave me peace of mind.

(I slipped in a couple of pictures from my trip.)

[Foley]

That's what I'm talking about Clarke!! Old trucks, nice clean mechanical upgrades, beautiful outfit you have there with the truck, personally designed and built camper, canoe, 4 wheelin', fresh fish, and your own box of Saran Wrap!! Appears that life is good over there in the mid west.

Foley,
Greenwood, CA

[Clarke]

Thanks Foley! Makes all the hard work worthwhile. I'm going to take a break this summer and enjoy it.

Next winter I plan to tackle the rust places on my body panels.

[OLDTRUCKHAULER]

Clarke,
Trailer looks good. I set up a 64 chbby 3/4 like your truck, with the wood rails
back in the USCG days. You should pull right well with the gears you should have by Thurs/Friday.

Mike OTC