Warning lights or gauges, were available in the dash cluster of the '60-'66 Chevy light-duty (C10, C20, C30, K10 & K20), medium-duty (C40) & heavy-duty (C60 & C80) trucks. There are some other series of trucks like the LCF & titl-cabs, etc., but I don't recall precisely. The tachometer was optional, as well as a VAC gauge & AIR gauge. The Tandem Lock & Overspeed windows are in all of the dash clusters, in '64-'66 and I don't recall on the earlier '60-'63 models, off the to of my head.
