mk3 tdi?

What needs doing to put a mk3 tdi in my 1.3 mk1?
i can get the whole car (rear ended) for 100 quid off my mate,  and it was a great runner,
is it  pig of a swap or should i carry on with the trusy 1.3 and chuck a 5 spee on it for comfort and less noise

same as any big block, chop bracket of driver leg and reweld further up, change all gear shifter and linkage, the mk3 will be cable shift so actually makes things a little easier (if it was rod shift you would need all mk1 5 speed parts)

wiring its not difficult to splice the ecu into mk1 if it has the later blade fusebox, basically same as this just ignore the coil part and instead of a fuel relay you'll be adding a glowplug relay. use mk3 glowplug wiring and fuse pop the large spade to N:
View topic: DX to ABF conversion wiring - The Mk1 Golf Owners Club

if its the early ceramic fusebox you can still do it but ideally i would change to the later one or even drop the mk3 fusebox in use mk3 engien and lighting adapted to fit splice MK1 dash and rear looms to it