Jim;
The only head I can think of , especially for '68, is the 1.5 head. I don't remember how many bearings it had, but, I do know it had smaller combustion chambers. A guy here in Conyers races Opels on the local tracks and this is a trick he uses, as it raises the compression ratio the easiest way. Plus, it's a dead ringer for a 1.9 head on the outside (visual thing).
The only head I can think of , especially for '68, is the 1.5 head. I don't remember how many bearings it had, but, I do know it had smaller combustion chambers. A guy here in Conyers races Opels on the local tracks and this is a trick he uses, as it raises the compression ratio the easiest way. Plus, it's a dead ringer for a 1.9 head on the outside (visual thing).