all courtesy of mr 'dizzie'..... read on!
Putting a mk3 dash into a mk2 is fairly straight forward, but very time consuming. I did mine in about a week's actual work - but draged over about 6 weeks. (it was xmas and cold outside!)
What you will need:
The whole dash from the mk3. I advise removing it yourself from a scrapper as you'll get an idea where various parts go and how they go back together.
All the switches... tip, to remove the headlight switch first remove the small cover to the right of it. put your finger behind it and you'll feel a small catch. push that in and the switch will come out.
All the loom's for the switches, heaters, everything!. You'll be cutting the plugs off and solding them onto your mk2's loom. Don't worry, all the colours are the same (god bless VW there!)
The huge metal support bar - The whole dash bolts to this!
The heater matrix and fan, etc. Easier to change the lot.
All the heater controls.
The stalks - may aswell while you're there...
Bascially everything in the dash area of the mk3. I bought the lot for £40.
Start by removing the entire mk2 dash. the mk2's steering wheel support is done with sheer-off bolts. you'll need to remove these and replace with 10mm bolts. You'll also need to drop down the steering wheel. the mk3 has height adjustable steering. If you're planning on using this you'll be bolting the support directly to the support bar. If this is the case make sure whoever welds the support bar in does a A+ job as when you get out of the car most of us pull our weight up using the steering wheel. You don't want the whole dash falling onto your lap! With alll the little bits of dash removed like the switches and clocks, centre console, etc the mk2 dash unbolts with 1 on each end which you can see. 2 under the rain tray (you won't be able to see those, just feel for them) and 4 which bolts 2 support peices to the bulkhead in the middle of the dash. It'll pretty much drop out then.
This is the first time you get to hold the mk3 dash in the car and see just how much you have to cut off the sides to get it to slide into the car. About 3/4" off each side (ish). with the help of a friend you'll need the dash held where it's going to go. then mark on the corners where the first cuts will be made. Once you've done this a few times the dash will start to sink closer to the windscreen. You'll soon find out that the underside of the dash is hitting the bulkhead...
You now have 2 options:
1) Cut away the bulkhead so all the heater vents remain intact. This would be the best option, but it compremises the car's stucture. If you want to weld in a strut brace close to the bulkhead then this option would be good. As I can't weld I went for option...
2) Cut away all the heater pipes to work around the bulkhead. This will then require some fibreglassing to get them back together. I currently haven't done the fibreglassing part as I want to sink my dash in a little further first. This requires cutting out my support bar and rewelding it in closer.
Anyway, back to the cutting. Once you've cut a fair wedge off the side corners the vertical peices that touch the door rubbers will be very close. You'll need to trim down there then. You'll also need to start reshaping the curve of the dash where it meets the windscreen. this is best done with the windscreen removed. Once you get the dash this close into the car there should be no gaps anywhere (unlike mine). You will have cut away most of the heater vents underneath now, this will require some thought into how you're going to reconstuct it later once the dash is in there perfectly. Using parts of the mk2 heater setup will help here.
Before you weld in the support bar you'll need to decide about your steering wheel. If you're not having it height adjustable then bolt it back in where it was with the mk2 dash maintaining the original position. You may need to drop it slightly to clear the bottom of the dash. Mine is dropped about 10mm I think. I'll raise it when I redo the dash.
Once you've done all the cutting and got the dash in there perfect it's time to get someone to weld the support bar into the car. In the mk3 it's bolted in. You'll need to cut off the mounting points where the bolts would go and weld it in. There is a small support piece in the middle you can also weld in too but personally I didn't feel the need as mine is solid anyway.
