[squidtone]

I just checked frame charts for a 67 chevelle, an el camino and 64-67 Pontiac A body. I'll assume 64-67 chevelle is same for sake of argument.

There's alot of measurements on the charts I viewed and Chevy and Pontiac used different datums in deriving measurements which adds to the confusion.

But, I compared the difference of distances between body bolt #4 (the one closest to the lower rear control arm mounting flange on the frame) and the very last body bolt #7 at the rear. (I don't know if Chevy numbered these body bolt holes the same)

El camino and chevy station wagons (not sure about 2door SW) are the same, and do have a longer frame behind the axle compared to the regular chevelle/malibu.

In addition, and pertinent to this post's question, the lengths of the el camino and chevy Station wagon frames match the pontiac Abody frame lengths/dimension, to within 1/16 inch; essentially they're the same. I didn't check out frame horn differences....I've read the olds or buick frame horns are significantly wider to accomodate side tank radiator core support.

Bottom line I think an el camino frame of the 64-67 vintage will work on a Pontiac 64-67 A body, and side benefit is the elco frame is boxed like a convertible.

By the way, the difference behind the axle in length from chevelle to A body pontiac/el camino/chevy station wagon is 3.5 inches, give or take 1/16"

(I erroneously wrote something like 5 inches in a different post some time ago...ooops)

good luck!