20V Cluster Tach Differences?

[BriceW at webtv.net]

I was having problems with my cluster. I had done the resoldering on the
check system and speedometer per Scotts site and everything was fine for
a few months.
Then my speedo started totally dying and coming back on and I found an
old post here that solved that problem about soldering a jumper wire on
the speed ground connections. That worked great.
But my circuit board had a crack under the resistor where you solder the
speed ground. The only problem I had then was that the turn signals
would not show up on the cluster. Then I started getting jumping speedo
again about a month later.
So I found a 1990 200 TQ at the salvage yard with 264,000 miles. I
bought the whole cluster for $50.00.
I then transferred the black circuit board to my cluster. I inspected
every detail and observed no difference in the 2 boards. I also switched
the check system board hoping to correct my brake pad warning light. I
also switched the clock as my clock quit working due to the plastic
inserts being broken and not being tight enough to conduct a signal from
the 2 square rubber pieces.
Now my cluster works perfectly. Some day I will need to resolder the
speedo and check system. Or I will just take my original check system
board and install it.
My brake pad wear light is still coming on.
You can get a new circuit board from Blau for $200.00 and a new clock
for $60.00.
I had heard that the ONLY difference between the 200 20V and the regular
200 TQ was the tach. I inspected both tachs and they looked identical to
me.
Does anyone know what the actual differences are if any between the 20V
and the regular 200TQ cluster and tach?