OK, here it is again for the 'new year' members. I'll buy the 73 dash for the right price
email me at
all4trux@snip.net
*,PLEASE READ ON FOR PROPER
APPLICATION. This is one of those items that is commonly mis-advertised as
73-87 when in fact there are several differences in each unit The first
thing to keep in mind is that GM did offer a Tach as an option after
1981 in light trucks,but they are rare as Hens teeth .I have found Canadian units that were supposedly from Mid 80's
trucks/blazers but the speedo is in KmH .It would be easy to install a U.S. MPH
speedo to it.There were 6 cyl. and 8 cyl. models available and a 6 cyl. one
is going to read high in a V-8 application. 95% are probably V-8's. Try to
know it works before you buy it. I have been TOLD that the 73-75 units are
NOT serviceable[I verified this now] and if they are bad, and keep in mind that ANY service will
probably set you back $125+ .I also found out Most of the tach repair places do'nt carry parts for our year tachs. The Light trucks were only offered with a
5,000 RPM tach but I have seen 4,000 RPM ones also. probably big diesel.
{when I say BIG ,I mean like a C-60/C-6000 series truck. The tach is easy to wire, but getting at least a short
piece of the factory pigtail to the back of it is nice to have, But not a
necessity. If you look close at the back of the tach it will tell you where
the wires go. many people don't know that there was a 'filter', that looks like a condenser, installed in many years of the factory wiring for radio interference reasons.It was mounted on the firewall behind the distributor. this is not a necessity .Speaking of distributors it does not matter if you have and old point ignition or HEI the tach still works.
As you can see the 78-80 gauges do not 'MATCH' the 81-87 NUMBERING style But this cluster will work in 81-84 as a
"plug in and go" unit But you will not have use of your factory Electronic cruise control that was used from 83-up. (the green box behind speedo). It is possible to work on 1985 and 1986 models also
depending on what you have still have in the way of the factory computer
[I.E.= if you have removed the factory feedback carb And ESC distributor,
Etc. and NO LONGER NEED FEEDBACK then it will be fine]. As far as INJECTED 1987 pickups go it
will not work on an 87 and will not work on INJECTED Blazers and Burbs from 1987 to
1991 because of speed sensor feedback needed for the factory EFI computer(ECM).IF YOU DO NOT UNDERSTAND THIS INFO THEN YOU ARE PROBABLY OUT OF YOUR LEAGUE OF CAPABILITIES WITH THIS-will be made by me to sell. if you have a 90-91 with optional ABS brakes then forget it altogether as there is a special crap hooked to your speedo housing that are not tranferable. The 1973
to 1975 models used an AMP gauge instead of the VOLT gauge and this can
cause major wiring problems (meltdown) if installed in later trucks equipped
for VOLT gauge or vice-versa. The 1976-77 used the volt gauge but had a
mechanical oil pressure gauge and creates a two year only dilemma of sorts.
If you find a 1976 or 77 unit with the VOLT gauge and the MECH. Oil pressure
then it can only be used in 76 and 77 models unless a complete and UNDERSTANDING wiring change is made in the later model wiring connector.It is not just a simple matter of using the mechanical pressure gauge instead of the electric. If you are Brave and think you can rewire it to be compatible and use the mechanical oil pressure gauge then something to keep in mind here is
to get at least a little piece of the factory oil line and fitting that was
on the back of the gauge. I say this because the factory gauge has a unique
type of ferrule and fitting on the back of the gauge that is good to save
and reuse. I have made aftermarket lines/fittings work but have also had
them blow off the back and make one heck of a mess. The factory used a
steel oil pressure line and I prefer that to plastic or you can buy 1/8" copper. Keep in mind that
there were also several variations of needle colors and the type of
lettering/numbers on the gauges. Mixing and matching gauges can create a
weird looking unit. The big trucks ,like C-60's are easily identified by a
tiny fuel gauge UNDER the tach and anything from a clock,blank , air pressure
gauge ,or vacuum gauge CAN be where the small ,round ,lower left clock option goes in a pickup dash. Some big trucks only had 4,000 RPM tachs also[and you thought a 5,000 was too low]. LOL.. Big truck tach dashes can be made to work in a pickup ,but offer many of there own unique problems because of optional gauges that were available in them and the years of compatibility and options mentioned above DO NOT directly apply to them. If you try to make a dash of parts & pieces bought you had better t know that you need the CORRECT printed circuit for your year truck/dash also.
The big things to get from all of this is 1.), AMP or VOLT gauge mix ups could= FIRE, 2.)Know it works! or BIG $$ to fix, 3.) 6Cyl. or 8 Cyl., 4.) 75% of sellers on Ebay Don't care about your concerns because I Email them all the time hoping they will correct their ad and they Don't. 25% are very grateful. ONLY 25%. this is a common statement I see in one guys ads AFTER i told him that mixing them up can cause wiring meltdown. QUOTE=" The cluster fits all models from 1973-87, but it may require some rewiring for units other than 1984 to 87 " thats BS!!!!!!!. YOUR WELCOME, DAVE