304 EFI cylinder heads differences?

[adamRSLC]

A good friend of mine has a bit of a problem which i hope a few of the V8 brigade can help with.

He recently gave his heads to a reputable machine shop to be recoed and cleaned up , his heads were off a VT hsv 304 ( the sequental injected ones ) and were in imaculate condition with onle 50,000km's on them. When picking up said heads last week he noticed when he got them back that there was some corrosion around the water jackets and the head bolts that were also given to him ( he never gave them any) were very corroded .

Upon closer inspection when fitting the original head bolts to the new head they dont "mark" the head surface the same way as the corroded head bolts do .

My hope is that there some external/internal difference between the EFI heads that would lead him in some sort of direction . He will speak to the machine shop on monday but some proof /facts will always help an arguement .

adam