I understand up until fairly recently some of the larger Chevy truck engines used the large, flat catalytic converters sometimes referred to as "pancake" or "turtle" converters. Does anyone know what years this might involve? I have a
1976 Cadillac 500 cid that came with this sort of unit (2 1/2 inches in and out, 19 inches long, around 12 inches wide and 3 3/4 tall), although it's no longer available and I haven't been able to find an aftermarket that would be right for such a large displacement engine--someone suggested a Chevy truck converter might work, providing it doesn't run too hot to be as close to the floor as the original one is.
TIA