For the record - for the general 74 MY 914 line, the biggest change was that the 1.7 motor was dropped for the "new" 1.8L unit.
Other 2.0 changes I recall offhand were -
EFI components changed in 74 (maybe some late 73 MY):
MPS was -037 in 73, then -043? in 74-76
CHT went to -012 in 74-76
probably some other EFI components changed too.
2.0 Air Box lid/top went to banded from diamond embossing in late 73 with early use of 74 MY parts.
Ditto for the black plastic door threshold & carpet strip pieces (from earlier aluminum ones) same as above.
OT Gauge went to the narrow red band as noted in the pix Jeff posted - both for the center console gauge, as well as for the newly substituted combo fuel/OT gauge which became a "standard eqpt." on non-center console 2.0's in 74 MY (see below re: de-optioning), & this is a good way to tell if a 74-76 914-2.0
may have been originally a base model with a console added later);
and changes to the main instrument bezels & plastic covers (from glass) as noted above,
but the 3 main gauges also switched to the black center buttons (from the older silver bullet style),
and the Tach went from left & right turn signal indicator lights to just a single indicator for both L&R TS (as VW used in all their cars through the 80's).
The rear 914 & 1.8 & 2.0 emblems went to black plastic (from the painted or anodized aluminum ones).
The LE option was offered mid-year, and the accessory negative side stripe decals came out, and under their "Personalization Program" you could order the LE look option on any 914 (paint scheme, painted wheels, blackout sail/rollbar trim, side stripes).
All Appearance & Performance Groups & individual options became extra cost options,
... after initially being "included options" on the USA's "914 S"/914-2.0 - and then late in the 73 MY wen the DM to dollar exchange rate increased the prices from $5299 POE West Coast to $7599 IIRC by the end of the 73 MY they started offering "de-contented/de-optioned" 914-2.0s with some of the PG or AG groups or individual options removed for a lower base price to help their advertising & sales rate.
74 MY Advert for 2.0 (courtesy of Jeff's website):
Click to view attachment.
vs. - 73 MY "914 S" / 914-2.0 ad from Dec. 72 (color one courtesy of Jeff's website):
Click to view attachment Click to view attachment.
Note that they used the exact same photo for both MY's adverts!