hey guys i have two chevelle frames one is 66 the other is a 67 i just noticed the rear spring perch diameter at the top on the 66 frame is larger than the 67 frame. the springs won't interchange. i thought maybe the 66 frame was a ss frame and the 67 was a malibu frame not sure any help would be great.my other question is how to read the vin on the frame rail. thanks have a good one.

I know the 66 frames have a spring retainer clip that holds the spring in whereas the 67 frames the springs just sit in the pockets. To my knowledge however the springs should interchange.

64-66 had a flat perch on the axle with a bolt-on retainer. The spring had a pigtail only on the bottom, and a full-coil on top.

67-72 had a cupped perch on the axle, so it didn't need the retainer. They had pigtails on both ends of the spring, and the upper frame pocket was shaped to accept the upper pigtail rather than the full-coil of the earlier cars.

so would i be right in saying that the springs don't interchange.and that a chevelle ss and malibu frame is the same except for the frame crossmember brackets.and would they use a 04-5-66 frame on a 67 chevelle.

so would i be right in saying that the springs don't interchange.and that a chevelle ss and malibu frame is the same except for the frame crossmember brackets.and would they use a 04-5-66 frame on a 67 chevelle.Correct, but you can use '64-66 springs on a later car, but not later springs on an early car.