Looking for some info on Impala FRAMES

[T-Type]

Hey all, hoping to pick some brains of all you knowledgeable folks here. I'm looking for a frame for a 1962 Impala convertible. What i'm wondering is what other years will work....i'm almost sure the 63 and 64 frames are the same....? what other years. also models? at this stage i can only guess the biscayne and belair used the same frame. also where are the extra mounting points on convertible frame? are they just regular body mounts that could be added to a coupe frame or was there something special about the shape/design? also assuming sedan and wagon frames will be longer.....

any help/thoughts are greatly appreciated. thanks in advance.