mr396

I found this in the January 1985 Hot Rod. It has part numbers for the speedo and the cluster lens.

JamesC

iTrader: (5)

Nice find. I recall seeing those speedo heads along with the gauge lens in the Classic Industries cat. a number of years ago. The speedo comes up in the classifieds from time to time.

JamesC

coolram62

iTrader: (2)

On the early cars ,'82-'84, that had the dual needle 85 mph speedo GM was kind enough to release a replacement ,over the counter, 140mph unit with the Z28 logo in the lower right corner. These were similar to the ones used in the '82 Pace cars. I found one on Ebay a few years back still in the OEM box. These don't requires a lens change since the trip odometer is located in the same place - you only have to convert to the '85 up units on an early car. It's a nice upgrade for both function and appearance.

two-if-by-sea

iTrader: (22)

Do you really have to drop the steering column? I've never seen that step before.

JamesC

iTrader: (5)

I always do. It makes working the cluster out a bit easier.

JamesC

TTOP350

iTrader: (8)

Didnt Gale Banks offer something like that also??

coolram62

iTrader: (2)

I second this and it's only a couple bolts and a strap clamp (not the right name) to drop the column down. if you don't it really makes working the cluster in or out aggravating.

drduster

iTrader: (2)

Thanks to this thread I've just acquired an NOS 140 mph Z28 speedometer, so I'm sharing the love.

I verified with the Parts Department at a GM dealer that the speedometer 25052189 & lens 25045478 are cancelled. I ran the numbers on partsvoice.com & found 2 of the speedometer at Craig Motors in Napa, California. 800-224-8111. $233.80 plus shipping. As of this moment, they still have one in stock.

The lens is offered from Classic Industries as a reproduction under the GM part number.

FormerL69

iTrader: (2)

Only problem I have with doing this upgrade on an '82 is that the font used for the numbers on the 140 mph unit is not the same as the font on the rest of the 82 gauges (or gages if you're GM ... ). The mismatch makes it looks wrong IMHO. That, and my poor Crossfire could never see 140...

It is cool that GM offered it.

paulo57509

Not necessary but I do it as well. Once the column is dropped (two bolts), I reach through the vacated space to undo the speedometer cable.

two-if-by-sea

iTrader: (22)

I've done it 3 times in the 4 years since I posted that question.

yo soy el warg

Since the same speedometer has come up that I found in an '84 maybe someone has found some information about the tachometer that was in the same cluster. It seems to have a factory number?

https://www.thirdgen.org/forums/hist...ch-no-red.html

Tri'all

so how do we find out specifics about our car?

Denoon01

I found an '85 IROC that I am seriously considering buying. After reading through various IROC sites and forums the only thing making me balk a bit is the speedo. It has the one mentioned at the top of this thread(140mph with Z28). So after realizing the '85's only came with the top speedo of 85mph I was became concerned. The car is a TPI, black on grey and only 29k advertised miles. It is spot on for what I have been looking for. Looks awesome, great condition. I don't see a reason to doubt the miles except the speedo. What is the chance the miles were messed with when the speedo was swapped out? I'm assuming that this newer speedo comes with a new odometer and must be spun to match existing miles on the car. It there any type of specialty tools needed that a shop would only have and therefore do a professional job and not screw around with the miles? Any insight would be great. Thanks.

FormerL69

iTrader: (2)

I am not an expert -- but my opinion is that odometers are easily tampered with if you know what you are doing. Brand new, these 140 MPH replacement speedos would have come with the odo set to zero.

All we can really determine is that the car has either 29k or 129k miles since the speedo was installed. What mileage it had before that nobody will know. If the speedo was installed when the car was new, you're good. A Carfax or AutoCheck might be able to tell you something, but there is no guarantee of course. If the speedo was replaced after some miles were on the car it might show up as a registration anomaly in DMV records.

Beyond that, I think it's impossible to say what the situation is.

On a historical note -- it is kind of funny GM actually sold these 140 MPH replacement speedos over the counter back in the day. Seems like the government would have created all kinds of red tape in order for them to sell something like this.

Denoon01

FormerL69
Thanks for the thoughts. Sort of the conclusion I was having a hard time putting together. So without documentation the mileage should be unknown. I'll have to think about it and make an offer with that in mind. Maybe it'll help get the price down.

FormerL69

iTrader: (2)

Glad to help.

There really isn't much you can do to research the history short of the usual suspects (AutoCheck/CarFax). Unless the owner has something that definitely shows the speedo was installed when the car was new and/or DMV records show a proper mileage history, it's a little bit of a gamble.

IMHO it's definitely worth you spending a few bucks to run a CarFax/AutoCheck to see what shows up. If you do buy it, the last thing you need to do is get tangled up in some kind of rollback controversy with your DMV if their records show something funny.

Good luck with it. Let us know how it turns out.