what year tach gauges are these? Also radiator bracket help

[hrc200x]

What year are these 3 tach gauge clusters from? The newer one I put a 85 mph speedo in it, it had a 100mph one which I knew wasn't right. I also put in a temp gauge that had the numbers rather than H and C. But I do think the H and C gauge that came out of it was the correct font/writing as the other gauges.

The two older ones are both mechanical oil pressure.

Also is a picture of a problem I ran into trying to install the radiator. Came out blurry where the problem is so I'll try to explain. The rubber that fits in the bracket hits the front main radiator support thing before the bracket itself tightens down with the 2 bolts. You can see the rubber is sticking out further than the mounting surface of the bracket. If I cut the back of the rubber off it might work, but would like to do it right. It might be rubber from a 70s model if they were different? Or the brackets could be a little short if there were different ones of them?

[BLE 'BURBAN]

The yellow one is a 73-74 model with an amp gauge. The lense free one is no newer than an 83 (Last year I believe) and the other one I couldn't tell without seeing the back side

[N2TRUX]

This one looks to be a 77+ cluster. It has Volts rather than AMPS, but you said it was mechanical oil pressure. I believe that ended in 77, so it might be 77 only.

[Prong]

The yellow is 73-75 (Amp gauge is a giveaway). The top one should be a 76 (single warning lamps in the tach/speedo area--77's have dual warning lights). And the last one is 81+.

[ElGracho]

The newest one could also be an 80, that's when they changed the script. The gas gage without "unleaded fuel only" makes it even less common. It must have come from a non-emissions truck.

[hrc200x]

Thanks for the help. Is it also true that using a amp gauge cluster in a truck designed for volt gauge can cause damage? Or is it vice versa?

If I remember right the yellow one came out of a Gentleman Jim. I see by ElGracho's sig that his is a '75 so that would be right.

The newest one came out of a '80 1 ton 4x4 diesel. The tach was covered poorly by electrical tape, but I belive the tach harness was partially in tact. I don't think diesels ever came with tachs, and if they did redline wouldn't be 5000 rpm.

Any ideas on the radiator bracket?

[Dooley]

Originally Posted by hrc200x

Thanks for the help. Is it also true that using a amp gauge cluster in a truck designed for volt gauge can cause damage? Or is it vice versa?

If I remember right the yellow one came out of a Gentleman Jim. I see by ElGracho's sig that his is a '75 so that would be right.

The newest one came out of a '80 1 ton 4x4 diesel. The tach was covered poorly by electrical tape, but I belive the tach harness was partially in tact. I don't think diesels ever came with tachs, and if they did redline wouldn't be 5000 rpm.

Any ideas on the radiator bracket?

The diesel was only available in the C10 in 1980.

[Prong]

The diesel tachs (very rare BTW) that I've seen only went to 4K.

[hrc200x]

Where does the factory wiring harness for a tach get power? There is a plug in on it that looks like it should clip into the fuse box but none of the alignment tab things are in the correct place to plug in. After that plug in there is about 3 inches of wire, then another plug in, female end I guess.

[Prong]

One of my 79's came with the tach from the factory and it has one of those fancy factory terminals that plugs in to the fusebox. On my other truck that I put the tach in, I just used a nice spade terminal to an ignition hot terminal on the fusebox. The truck is in a million pieces at the bodyshop right now, so I can't get a pic for you too soon. BTW, you WILL fry wiring if you plug a Volt gauge cluster into an Amp wired truck and vice versa.

[Captkaos]

73-75 is the yellow one
76-77 is the black with the lense (mechanical oil)
80-81 is the new script one without a lense.

As for the radiator support, what year truck are you working on and where did the brackets and radiator come from. It looks to be the wrong isolators...

[hrc200x]

I'm surprised chevy even made it so you could plug a volt cluster into a amp wiring harness and versa vice.

My one tach harness does have the factory plug in, it just doesn't have the correct alignment tabs to fit into the fuse box or the box doesn't have the correct ones to accept it. I'll try to get a pic sometime.

The clip is a '88. Brackets I'm not sure what year, guessing a 80s with out A/C? Didn't the non A/C trucks have the lower radiator? Rubber pieces might have come from a 70s, radiator I belive is a 70s. I have rubbers from a 80s, and the back of them that is getting pinched in the picture doesn't happen on the 80s ones, but they don't span enough to reach accross the radiator to hold it. Maybe these rubber pieces along with the brackets changed from 2 to 3 to 4 core radiators.

[ElGracho]

Originally Posted by hrc200x

...The clip is a '88. Brackets I'm not sure what year, guessing a 80s with out A/C? Didn't the non A/C trucks have the lower radiator? Rubber pieces might have come from a 70s, radiator I belive is a 70s. I have rubbers from a 80s, and the back of them that is getting pinched in the picture doesn't happen on the 80s ones, but they don't span enough to reach accross the radiator to hold it. Maybe these rubber pieces along with the brackets changed from 2 to 3 to 4 core radiators...

With the mix and match on parts, I'm not surprised you are having problems. The 73-80 and 81-87(or 91 burb/blazer/crew cab) radiators are different.

For just 81-87 there are at least 5 different radiators/upper bracket combos. 6 cyl small/narrow radiator, the standard small block v8 radiator (deep dish on the upper fan shroud), HD cooling small block v8 radiator (shallow dish on upper fan shroud), big block v8 radiator (no dish on upper fan shroud, wide flat top bracket, and the diesel radiator (super wide by super tall).

To make it fit right you'll have to get a late radiator and the brackets and fan shroud that match.

[hrc200x]

Is there a how to on resetting the odometer, preferably with pics? I found one, but it didn't say what year its for, the guy that wrote it signature said he had a '72. Is it the same as older models?