need a MK2 GTI head on the 2.0 to make it plug n play, use your old flywheel and box + a new clutch kit and it drops right in same way old one came out. i suspect your head could be warped if it was allowed to overheat, so a skim or replacement head would be a good plan. use 2.0 head gasket and timing belt, and 2e dizzy if its a later 2.0 8v you get. I got a 2.0 8v lump for £40, 150 a bit steep, and 50 a bit steep for a 1.8 8v lump really, common engine to find. i struggled to give my 1.8 bottom end away. I know of a 1.8 lump going in west london area, if hes still got it that is