Actually the only major difference between the 87s and 88s, engine-wise, is the alternators. The 87s had external fans while the 88s had internal...
Anthony
Do you mean you don't want to mill the head anymore than you have, or do you not want to port it :shrug:
You could try a better set of gears...The only other option I can think of for N/A is a nice port and polish, possibly a 3 valve job :D
Anthony