Level of difference varies depending on the year.
- The suspensions are the same. 1600s from 1966 - 68 lacked rear sway bar mounts on the subframe, although they can be easily attached. In 69 they equipped the 1600 with front and rear sway bars just like the 2002.
- All 1600s (except the 1600ti) had smaller rear drums (200mm vs. the 230mm of 2002) The first couple hundred 2002s off the production line in 68 also had the smaller 200mm rear drums. The larger 230mm drums of the 02 were adopted from the 1600ti. 66-68 1600s used the earlier style remote brake booster. In 69 the 1600s were equipped with the more familiar brake booster which first appeared on the 68 2002. The 68 2002 and 69 1600 use the same brake master with attached fluid reservoir. All 02s up until about mid 69 used single circuit and single piston brake calipers, identical on both 1600s and 2002s. In mid 69 both models received the 2 piston calipers.
- Rear subframes on both models were designed for the longneck differential up until late 69. The 1600 used the 4.10 diff while the 2002 used the 3.64 ratio. Many other ratios were available if specially ordered. Some 1600ti's used the 3.90 longneck diff. In 1970 both cars were being equipped with the newer short neck diffs and corresponding subframes.
- Driveshafts differed on the 2 models up until both models received the short neck diffs sometime in 1970. From that year both models used the same driveshaft. All 1600s with longneck diffs used a unique driveshaft with a telescopic - sliding center section and no u-joints. These driveshafts used 3 6 hole guibos and corresponding 3 hole flanges on the tranny and diff. Longneck 2002s (1968-mid 69) used a similar driveshaft with the telescopic - sliding center section, but differing from the 1600 driveshaft in that it used u-joints at midpoint and rear. Up front at tranny the 8 hole guibo with corresponding 4 hole flange on the tranny was incorporated. A 4 hole flange at the diff was also used. The switch to u-joints was done due to higher torque of the 2 liter motor.
- Transmissions also differed up until the factories switch to the short neck diff in 1970. Prior to this year both cars used the smoother shifting Porsche-Synchroed trannies. The 2002 tranny, though, used a longer shift fork to clear the larger 8 hole guibo. You can use most trannies on a 1600 (given you also switch the flanges - all being of coarse splined design - some late 02 trannies were fine splined), but you can't use an early (66-69) 1600 tranny on a 2002 because the shorter shift fork can't clear the larger guibo. All trannies and driveshafts were standardized when the factory switched to the short-neck diff.
- All 1600s and 2002s with the single piston calipers also used a unique inner front wheel bearing. This bearing has the same outside diameter as the later bearings, but the inner diameter is 2mm larger from the later style. The spindle at this inner point is 2mm beefier than later models.
- The very early 1966-67 1600s used a different style muffler and resonator. In 68 they standardized the exhausts on both cars. Exhaust
- and intake manifolds are different on both cars. The single barrel carbs differ in that the 1600 uses the 38mm butterfly while the 2002 uses the 40mm. Chokes and jets on the two single barrels also differ.
There are many cosmetic differences between the early and later cars.