Larger gearbox tunnel, drive shaft tunnel and diff tunnel.
fabricated ready for you to cut your old one out and weld in, complete front tunnel, through middle and larger above diff - 3 pieces
If just using front there will be a step to fill in to original, some fettling required
Front EF1964 $185 plus gst - full set EF1964/1965/1966 $345 plus gst