I, like a lot of guys on the board want to get rid of the “crumbling” cluster problems, dim dash lights, and 40 year old electrics, but wasn’t quite sure what to do. I’m no different, but I wanted to do something, so about a year or so ago I bought one of those fiberglass six hole gauge clusters from the guy in Brazil. It looks fairly nice, but once you decide where to locate it the install is a little more complicated than a simple bolt on if you want it to look nice. I rarely ever photograph what I’m up to because for those of us that have built or restored a ton of old iron, or make our living in the car business, it’s just second nature. For the weekend warriors and newbies, sometimes it helps to share a few thoughts on how some was done that might save someone a few hours of grief, or maybe give them the kick-start they need o take on a little upgrading. We’re having some bad overcast here, so forgive the picture quality, but hopefully you’ll get the idea and maybe it will be helpful to someone. There is always 50 different ways to do something – this is just one way to do, so take it for what it’s worth. Upgrading the dash is not exactly cheap. I went with Marshall gauges because they make a good product, they have a reasonable price point (8 gauges run right around $425 on ebay), and they have a stepper motor gas gauge that works with a variety of applications, including the original Maverick sending unit. I went with the black face gauges based on preference, and the look for the period of the car, but white is available too for those so inclined. Since the car is my son’s daily driver, I didn’t want to disable the car while doing the install, so I got another cluster for the build-up, and I’ll swap it out with the one in the car when its done. The cluster modification is fairly straightforward. All you need is a bare housing. Remove the printed circuit, gauge housing and the glass. Use some heavy paper (oak tag), or cut up a file folder to make your pattern. Paper needs to be 12” wide, so use a legal folder, or tape two letter size folders together and cut it to size. Get your scissors, take your time and cut the pattern to fit around all the little obstacles on the back of the cluster. Let the pattern “float” on top of the 4 locating plastic pins on the rear of the cluster. Once you are satisfied with the overall fit, push the pattern down (gently!) on the locating pins so you mark the location for the holes. Cut your holes and check you final fit. This is not rocket science, and you’ll never see 99% of the panel, so getting everything within 1/10,000 of an inch is not necessary – you just need a good clean fit. Once the pattern is located on the pins, flip the cluster over to mark the outline of the gauge openings. Remove the pattern, and mark the centerline of each gauge opening. Measure the distance of the centerline and find the exact middle to draw your “crosshair” so you’ll have a reference point for your hole saw. Find yourself some 22 gauge sheet metal at Home Depot (12” x 7” minimum) and transfer your pattern to the metal. Using a black thick Sharpie works nicely, and if you cut to the inside of the Sharpie line, your metal will match you pattern exactly. So grab you tin snips and have at it. Next, use an awl or a nail and transfer the 4 holes for the locating pins, and the 2 centerline holes for the gauges. Place your metal back on the cluster and double check that your pinhole “dimples” line up with the pins. When you are satisfied, drill the four pin holes and make sure everything lines up. Flip the cluster over and make sure you locating “dimples” for the gauge centers still look centered. If anything is off, NOW is the time to correct it. Use a hole saw to cut out your gauge openings. Do this using a backing of plywood, or something flat under the metal. Be gentle, as the sheet metal bends easily, and it doesn’t take much for the hole saw to cut through it. Once everything is cut and fitted, wipe the face of the metal with lacquer thinner, hit it with some primer, and finish it up with Duplicolor “Trim Black” paint. The four locating pins will be used to hold the panel to the rear of the luster, but they can’t take ANY torque whatsoever (ask me how I know!), so using self taping “hats” or anything like that won’t turn out well for you. The easiest way is to fit the metal to the back of the cluster, press down securely, and use a soldering iron to carefully melt the pins to form a “mushroom cap” over the top of the metal to hold it in place. Make sure when you melt the pins, you keep slight pressure on the metal for about 60 seconds to allow the plastic to harden back up, otherwise the metal will pull up past mushroom cap and you’ll have a real problem fixing that mess (again, ask me how I know!). Now you can mount your gauges, and find some LED’s for the idiot lights. The advantage to the metal support is that it can be used as one giant “ground” plane for all your ground connections too. Next is the 6 hole housing. The shape of the housing is not exactly a good fit to the curvature of the dash panel, so just bolting it on there will leave a lot to be desired, unless you don’t mind seeing gaps here and there! The first step is determining where you want to mount it. Put some touch-up paint on the end of the mounting lugs, and press onto the dash to mark your hole locations. Drill the holes and install the housing. Use your Sharpie to draw the outline of the housing on the dash panel. Remove the housing and cut out the dash with a very small cut-off wheel (Dremel), or an air saw, which works great if you have one. Cut the opening square, leaving material around your mounting holes. Using a hole saw to cut six individual holes in another option, but it’s a ton of work and difficult to line up right, so you’ll still have a ton of final trimming to do anyway. After you’re done, mount the panel to the dash, and test fit the gauges to each hole to make sure they slide in freely – it easier to deal with interference problems before you bond it to the dash than after. Once you’re satisfied with the fit, run a bead of epoxy on the mounting face of the housing, install in the opening and secure (gently) with the nuts on the mounting studs. When the epoxy dries, use masking tape on the inside of each gauge opening to seal-off any gaps between the housing and the dash. Mix up some filler (Bondo) and use a small Popsicle stick to fill the voids. You can use the stick to smooth the filler, especially on the top and bottom edge of the housing, which dramatically cuts down the time you’ll spend sanding. Before the filler fully cures, use a razor blade to scrape off as much excess as possible – any amount that you can get rid of is that much less sanding dust you’ll have to deal with. When it sets-up, do you finish sanding, wipe it down with mineral spirits or prep-sol, and hit it with some high build primer. Make sure all the imperfections are gone when the primer is on – if not, go back to sanding until its right. It goes without saying that making this modification is a big time commitment, as well as a major hassle. The entire dash will need to be refinished, so make sure this is something you really want to do because once you start there is no going back. This is about as far as I’ve gone right now, but I’ll try to add some additional detail on the wiring, final painting, and how the final installation turns out as I get to it. I am going to use three buss-bar type terminal blocks just because of the number of gauges involved. One for ground, one for 12v switched, and one for dash light feed. Also, Summit make a nice 15 pin, quick disconnect connector for the speedo cluster so you pull it in and out easily to service something if the need arises. If you are going to do a project like this, check ebay for pricing. The connectors and blocks are available in your local marine store, but you’ll pay triple retail for them!
Looking great so far!! That is how I plan on mounting my gauges in the cluster as well. I was planning on weling in tubing for the other gauges. I have never seen the fiberglass panel. Where exactly did you get it? Do they make a four gauge panel?? Looking forward to more pictures....nice job on the article.
There is a guy from Brazil that posts fiberglass parts on ebay. He posts once in a while, so you never know when he'll show up, but I think he might be a member here on the board as well. I think he only makes the 6 hole version if I remember correctly.
don't cut it just buy a few extra gauges like / vacuum / boost / (for when you get that blower) clock / exhaust temp / and whatever you think you may use in the future
