Magnus

iTrader: (4)

The electronics assembly behind the cluster is one big assembly, You can't just "remove" and add a different coolant temp gauge.

SScam68

iTrader: (20)

Thanks for letting me know. I was about to pull it apart this morning.

Cal

iTrader: (1)

It may very well be that the only problem with the stock tach is excessive dampening; if this is true there may be a mechanical fix for that, e.g. just making the needle move more freely. If the tach is electronicaly damped, there may be fixes for that also, assuming the dampening is not done with software in the PCM. In the GM circuit diagrams, the tach signal does come out of the controller module, but at that point it may look like a standard tach signal. The way to find out for sure would be to simply hook up a standard tach at this point and see what happens.

Cal

iTrader: (1)

I know it is one big assembly, but anything that can be assembled by one man can also be dissembled by someone else, it's just a matter of having the tools and know-how to do it. I think the bigest problem is you will have to buy a complete new cluster just to get the one gage off from it. That will be very pricey form GM, but from a wrecking yard it may be affordable.

LS1 PWRD

I dont know if this will help the tach discussion or not, but when I went to install a tach in my LS1 powered Astro I ended up with a 4 cylinder tach because the 8 cylinder tach read exactly twice as high as my scanner and I know the LS1 wont rev 12000rpm. It looked good on the tach thought at 9999

02BlueFirehawk

My tach is accurate to about 4000rpm and then slows down to almost 500rpm slower than actual. Car will be hitting 6300 rpm and it'll be reading 6000.

98form

iTrader: (5)

I was doing a search on this and found this thread. Good info, but no solution. I have 2 98 LS1s and both of them show and idle of around 1100 rpm on the stock tach. I have a scanner that reads live data and I have confirmed that they are both idling around 800 rpm. It seems from reading this thread that the later LS1s have more accurate stock tachs than the earlier ones. Most with 98's reported symptoms similar to mine while 01's & 02's seem to be pretty accurate. I like the stock look and don't want an aftermarket tach or shift light. Did anyone ever come up with a solution?