True Connections

This month we are going to discuss the 1964 and 1965 Chevelle and El Camino instrument clusters. The standard cluster is commonly referred to as idiot lights since they had a warning light for the amperes, temperature, & oil pressure on the right side. On all Super Sport models, GM decided to installed a set of actual needle gauges in place of the lights. But it wasn’t just the 4 gauge cluster that was changed. It was also the housing, the speedometer lens and the lens backing plate, so a simple swap cannot be achieved. So if you are planning on converting to gauges you cannot use your existing cluster at all. Sure, the speedometer and whatever you have in the center hole will interchange, but you must also find the lens and backing plate to accommodate the needle gauges and the back housing is a different shape. Those pieces can prove to be more difficult to find than the cluster itself. Not only that, once you get the instrument cluster together now you have to change all of the wiring. Remember your idiot light cluster used a simple light bulb, but with gauges it uses multiple strands of wiring except for the oil pressure gauge, which is mechanical. Now there are companies out there that will sell you a so called 'conversion kit' but this thing they have is garbage. You have to hack up the housing and backing plate, and when some customers called up asking us if there is something better, they have said the lights inside their dash have actually melted their gauges since these conversion kits are made out of plastic. There are currently very nice reproductions of the factory gauge cluster and idiot light cluster, but again, you can't put the cluster of one into the housing of the other.

The 1964 and 1965 gauge clusters look very similar but they are in fact very different. The easiest way to tell the difference is that the 1964 cluster has an open element type of internal windings. Basically this means that when you remove the 4 gauge cluster from the instrument housing, and you look between the face and the back mounting plate you can see the electrical windings. The 1965 model has a cylindrical metal shield protecting those windings. The first difference in the clusters is that in 1964 GM used a fuel tank sending unit that went from 0 to 30 ohms, but in 1965 they changed over to a sender that went from 0 to 90 ohms. Fortunately the sending units can be changed over but that’s just the first hurtle. The second problem is that the 1964 gauge cluster used an external shunt for the amp gauge that was mounted on the core support. Without that shunt the gauge will not read properly, however they are now available reproduction. The 1965 amp gauge was shunted internally which made the gauge internals slightly larger, so the amp gauges by themselves cannot be interchanged.

In the center of the cluster was either a clock or a block out plate. Or, if you were a really big spender you could have had a tachometer in the center of the cluster. In that case, there was another option that was a dash top clock which was mounted to the right of the driver on the very top of the dash. In 1964 there were actually two different dash top clocks, one for use without a dash pad and one for use with the dash pad. Both were considered at the time to be relatively ugly and looked almost as if they were an afterthought. The 1965 dash top clock was the same for a padded or non padded dash, and was clearly a more stylish piece. That clock was the same as was used as an option in 1966 models when gauges were installed without a console.

The in dash clock for 1964 looked very similar to the 1965 clock and they will actually interchange, but there are a few subtle differences. The most noticeable difference was that the 1964 clock did not have a hand to count off the seconds. Another difference was that the stem to adjust the time was much longer on the 1965 clock. Next month we will discuss installation of 64 and 65 instrument clusters.