I don't know the model letter. The elco is an intermediate(midsize). The front and rear suspension is the same as '68 to '72 Chevelles,Elco's,Buick Skylark,GS, Pontiac LeMans,GTO and Olds Cutlass ('70 to 72 Monte Carlos too). Also known as "A bodies". The '64 to '67s have a 1 inch narrower rear axle but all years will bolt up. The disc brakes from later years will bolt up at the ball joints to get rid of drums on early years.