Interesting question, all my knowledge is on 8v PB GTi engines.
ClubGTi give us the following information:
Lump codes
1H - Rallye G60 -1989-1991. 160bhp
PG - G60 -160bhp
GU - 1.8 8v carb. Golf driver, syncro etc.- 90bhp
AAA- 2.8 VR6, Golf, Passat 1002-1997 - 174 bhp
ABV - 2.9 VR6, Corrado, Golf syncro -190 bhp
PB - 1.8 8v Digifant, Mk2 GTI '88-'92 - 115bhp
9A - 2.0 16v -
KR - 1.8 16v. golf GTI - 139bhp
ABF - 2.0 16v. - 150bhp
Audi Engine codes
VW Engine codes
This indicates that the lower end of your engine might be a GU and not a PB hence the PB advice could be wrong:
2E – Probably the most common, found in the early (pre 95) MK3 Golf GTI 8V’s. Also found in Passats from the same era.
AGG – Found in late (post 95) MK3 Golf GTI 8V’s.