quote:... so, the ZF-1s used in early panteras have the same smaller and lighter, but also weaker bellhousing/case combo as the GT-40s/mangustas??
Yes- not all, but possibly your #1267 pushbutton. RBT refers to these transitional transaxles used in a few pushbutton Panteras as "dash- 1-1/2" assemblies, since they use a later Pantera 'dash-2' differential case in the upside-down configuration a Pantera chassis needs, with a flipped-over 'dash-1' Mangusta gearbox in the middle and a Pantera end-cap. A few still have the low 4.50:1 Mangusta gearing in the ring/pinion, in place of the 4.22:1 ring/pinion like later Panteras. This produces shattering acceleration but only 135 mph at 5500 rpms. Most US Panteras were changed by Ford under warranty and the fragile transitional ZFs scrapped.
Check the number of bolts holding the bellhousing onto your engine, and whether the bellhousing has two 'windows' or only one. Such 2-hole bellhousings were sand-cast so they're rough, while later units were die-cast and are smooth. Such early Pantera transmissions share the same problem as the Mangustas: an almost total lack of spare parts specific to this transmission, although Roland Jaeckel in Germany may still have a few parts. Please don't ever break anything!