Yeah I also use the larger filters, takes a good 4.5L of the 5L quantum platinum stuff I buy! lol
you got the part number for the larger filter,and whats the thinking behind it? just to have more oil going through the engine? im on 193k miles on my 98 AGU and i use fully synth oil from VW.
also,is having the oil pick up replaced a major job? im having a big service on the golf soon,and im trying to pre-empt any problems so im tempted to get that done as well.