according to "Chevrolet by the Numbers, 1965-1969" by colvin:
"1967 through 1969 camaro.
This rear end assembly is a Salisbury design similar to the 1968 chevy II rear axle. The differential does not have the upper control arm mounting 'ears' that are cast into the Chevelle center section. All 1967 Camaro rear axles are mounted on mono-leaf springs. The leaf spring pedestal mounting on the rear axle is the same as was used in the (see below) Chevy II, although the mounting pads are slightly canted or tilted inward."
the book quotes "1967" here, but when i compare the axle specs from the book, i believe it is a misprint as the axle width and spring perch centerlines are different. However the 1968-69 Nova specs are the same as the Camaro's.