[Greg Reimer 7376]

The best thing to do with a car not in the current Moroso or anybody else's catalog is to go by vehicle weight. That works pretty well with station wagons being the exception due to the weight bias. Moroso springs settle after a while,dropping the ride height a few inches, then weight transfer is impared.Fortunately, a 65-70 B body big car uses a spring dimensionally close to a Chevelle. If the '66 is a 2 door, like my old P/SA,it weighed 3690 with driver. A 66 Chevelle wagon weighed about the same, so a 327 A/C spring from the Moog catalogue probably would be dead nuts from that application.In our 68 Chevelle wagon,I used a big block spring, it set the car a bit high, but over the years, it has settled in about right.I used a 70 Chevelle big block rear spring and some gas shocks, and the car's suspension has been nearly trouble free since I built it 14 years ago.Six cylinder applications are not always advantageous-- the old 235 cubic inch 6 from 1962 on back, especially with a cast iron Powerglide in actuality probably weighed as much or more than a 348 or a 409. It definitely outweighed a 327 by 200 or so pounds. Shocks, bushing material and chassis preload, as well as other factors have as much to do with how the car works as anything else.On a Chevelle, the right rear spring is as critical as the left front in how those work, the 66 probably isn't much different in that regard.