A -2 ZF will have the bellhousing attached to the main case in 7 locations ( 5 from the outside and two inside the bellhousing) A -1 will only have 4 ( with 2 additional bolts between the bellhousing and the side plates.
Also the -1 will have 2 small " windows in the bellhousing and word " DeTomaso " cast into the starter hump. A -2 will have one larger " window" on the driver's side.
The input shaft is slightly shorter in the -1 and a different diameter ( both 10 splines)
Ron