MG MGB and MGB GT Tech Talk
I have a 1970 "pillow" dash, it's in fairly poor shape, and a lot of the instruments are not functioning. I managed to pick up a 1977 dash and radio console with all the instruments in them for next to nothing. Would this conversion be a headache? It looks like the bolts are all in the right place, but what about the wiring? Should I sell them and go for a 72-76 instead? I do want a glovebox and I hate the pillow.
The 72-76 would be a breeze since the steel backing is identical except for the vent and glove box cutouts.
The late dash has all kinds of cool little lights that yhou would have to wire to. Also, check the tpm of the speedo head. May be different than what you currently have.
I'm performing a similar conversion on my '69 GT using a late-RB dash. The only real difference in gauge/control placement is the heater controls are down on the console so background lighting wires will have to be extended. The RB dash has a place for a clock so if you plan to use that, you'll need a light and wiring to power it.
Other than that, wiring layout isn't too much of a problem (he says optimistically as he prepares to accomplish the task).
The RB dash will bolt right on but keep in mind, you won't have any face-level vents unless you cut holes in your '70 firewall. Or just put in a cool Nav system in place of the vents.
You can use your original instruments but since your tach and speedo are 80mm units and the later dash uses 100mm openings, you would have to make up a spacer. The smaller gauges are the same size either early- or late-style dash.
I could well be wrong and look forward to being corrected, but but I think all 100mm (late RB) speedos are 1000tpm and 80 mm speedos are 1280tpm.
Interesting to see someone else doing this. Are you using the late instruments, if so what's your take on the speedo issue described above? I think I heard this from elsewhere too...
Yes, the speedo thing is correct.
Here's the history:
<= 1967: 1000 TPM
1968-1974: 1280 TPM
1974½-1980: 1000 TPM
Unfortunately the big speedos only come in 1000 TPM.
http://www.gaugeguys.com/Smiths/classic.htm
http://www.gaugeguys.com/Smiths/telemetrix.htm
I'm thinking of going with one of the above gauge sets. The first is the classic look we all know and the latter one is a more updated look. The advantage of the second link's speedometer is it's electronic so calibration isn't a problem.
To add to my issues; I've installed a Nissan 5-speed using the Rivergate kit which includes a speedo adapter. Once I get the car on the road and I check for speedo accuracy, I can swap it with Rivergate for another adapter if required.
I find the RB gauges a bit plain for my liking. As shown on the two links, the gauges are available in either 80 or 100mm sizes.
If you plan on using stock gauges, you can get them recalibrated. I had to do this on my V8. Speedo is bang on but odo is out a bit. Guy that did the job told me I could have one or the other accurate but not both. Odo error is minimum.
Interesting about the recalibration. Probably an MG specilaist garage could do this? How much did the recal cost you?
I redid my dash and I'm thinking about using the vent holes to mount speakers in. Mg's never seem to have speaker placements which work very well, and this should. Comments?
Recal was cheap at about $50. All I had to do was check the installed speedo against another car to give him some numbers to work with. Up to about 40 mph, it was pretty good but by the time we got to 70, it was reading high at around 80 or so.
With these numbers, my tech guy (who's an avionics technician by day) got the needle set up properly. If you have a look in the "search" feature on here, you may find some info on shops in the US that may be able to help you out.
I converted the GT to a 73/75 dash from the "pillow". Not hard - but you will need to do the console too as the pillow version will not fit well with the later dash. Wiring is not a problem.
I put a metal panel (painted "hammered" black) in the vent hole and installed a boost gauge, voltage gauge and O/D "on" light. Unfortunately, Smiths do not make a "classic" boost gauge, so I used "AutoMeter" - they look similar (chrome bezel, black face with white numbers) but they have red pointers. I was hoping I could open them up and paint the needles white - but no luck. Fortunately, that are seperate from the other gauges so they don't clash too badly. If I remember, I'll take a picture when I get home and post it.
The panel I cut to size from 16 gage (I think) steel, then welded captive nuts on the back to accept threaded rod loctited in place. Then I was able to use the same retaining bar as the vents use, with two nuts to hold it in place.
As promised - a pic of the '73 dash in the '71 GT. I intend to add the remainder of the center console and armrest at some point.
Thanks Eric,
I have been contemplating doing a '73 dash into my '68 GT. You now have me fully convinced.
Wow! Looks very nice!
Well, after all this advise, I think I will try to sell my 77 dash and radio console, and look to getting a used 72-76 dash.
If anyone is looking for the late dash plus a radio console, both with most instruments in place, let me know. Also if anyone has a 72-76 dash available.
lolol! The poor, poor pillow not getting any love! Gloveboxes are overrated anyway. When was the last time anyone put gloves in there?! lolol!
JMoore Wrote:
