I wasn't aware that there were differences between the early and later cars? It can't just be the magnum range that had the V shaped bracket - both my '72 sport SL and '78 magnum have one of the V shaped plates with two hangers on bolted through the floor (actually the Firenza has two now - to support my twin pipe system, I ended up making the second one, if you go this route make it rigid or the bloody thing vibrates like mad against the floor!)