You need an ABF donor car, as you'll need pretty much everything if you're going from a 1.8. Depending on what year your chassis is, it may have the hydraulic clutch cutout which will enable you to use the hydro clutch rather than having to convert the 02A box to cable change. You'll need the gearbox cables, hydro clutch/conversion kit (I think the 16v Seat's had clutch cables on their 02A,s you'll need parts from them), you'll need 16v engine, 16v gearbox, 16v driveshafts, 16v hubs (I think the last two may be the same parts as an 8v), you'll want bigger brakes rather than the 256mm ones from a 1.8, you'll need radiator, wiring loom, ancillaries, probably fusebox too as you're coming from a non GTI model. To be fair, it's probably worth selling the 1.8 and just buying a 16v
