Right,
Top End
Get a copper gasket much less chance of warping
Head off, skimmed and flowed.
Cams, check for wear on them and will probably need replacing.
New Tappets, Valves and valve springs will need changing both exhaust and intake.
Pistons will need replacing regardless as they will have worn, get a .5mm overbore don't bother with a .25.
Have them polished aswell, basically so it gives a smooth movement for them during the engine turning.
Bottom End:
Big Ends (or Shells) take out and replace whilst there check the crank, this will have worn but if its only aboit .5mm then it should be ok, i personally would replace it.
Whilst in there and the sump is out, pull out the oil lines and clean them out, might also be worth replacing the oil pump.
errrm, hmmm.
1. do not under any circumstances skim the head unless you have have a real reason to do it - like something is warped and when you had a major headgasket failure. if you have the head skimmed then you reduce the distance between the top of the pistonhead on the head for combustion. this leads to the head running hotter and causes other problem. if you've had a big head gasket failure this is somehting you'll have to live with - if you haven't had a head failure then you are merely maknig trouble for yourself. If it aint broke dont fix it.
2. do not go 0.5mm oversize rebore if you don't need to. there are oil galleries at the bottom of the block that get screwed on anything more than 0.25mm. 0.5mm and you are heading for problems - so if you can avoid it - try to. Again - if it aint broke don't fix it.
3. not sure what you mean about the piston being polished. unless you mean the bore. i can't see why the pistons need polishing? its the rings that touch the bore not the cylinder. however, if you have the bore polished then you are doing more harm than good. the rings need to make a good fit with the bore wall and they do this by leaving the bore rough. this roughness give the rings something to bed into and create a better oil seal and a better gas seal which is what you want.
4. copper gaskets should only be used on engines that require copper gaskets. use the standard VW gasket - it will do the job properly.
