Very few Garretts about, think might have been early ones, or randomly dotted amongst production, but I like them mots, seem mechanically a bit stronger
No, the CHRA (middle bit, bearings and shafts) would be substantially the same, but the turbine and compressor howuings as well as the wheels would be different...
The manifold bolt configuration is 'per vehicle model' but also the Aspect Ratios of the wheels and housings (the gas flow and pressure ratios it's designed for) is also different. So a K14, covers a range of exhaust and inlet airflows, and a K24, larger, another range. Within that, there is a spread of housings that can be used fro each one.
But the main thing is that externally they won't bolt up or plumb up to all yor engine's dangly bits.
The K14 and the T2 seem to be just a shade on the small side exhaust wise, so they spin up and boost well early on but produce higher than ideal back pressure and EGT when cruising, esp. if you try to overboost them much. They will produce 12-14 psi with a wastegate bleed (7.5 std) but then heavily choke the exhaust flow...