Re: gear queries
Best bet would be to chat to a few gearbox reconditioners, they should know what gears are interchangeable from what boxes. If it's a manual, v8 Falcon manuals are rare as rockinghore shit, so adapting the gears is probably your best bet.
If it's an auto, my suggestion would be to put a manual in it, failing that a better diff such as a 3.45 or 3.77 should be the go.
Proud TQE Operator and President of SEFAG - the Society for the Elimination of Ford Automatic Gearboxes
Pacemaker headers + 2.5" exhaust
EF Fairmont interior
Lowered King springs
5 speed manual
Newest mod: EF Ghia wiring loom and dash