Looking over my records, mine(83.5 = westy) were changed at 92,000km in '88 and again at 217,000km in '94, both repairs = included new heads. I now have 232,000km on the odo in '99 and no leaks so the = longevity roughly brakes down to-
first set:  92,000km / 5 years
second:  125,000km / 6 = years
current:  115,000km / 5 years = and counting
Oddly the two repairs seem to of = outlasted the factory ones. I only took possession of it at 270,000 so can't attest to = driving conditions/style of previous owner. Jim
 
 
Questions
What is the = furthest anyone has gone with a wasserboxer 1.9L engine without
a leak so bad it needed fixing? 
And once = it starts leaking how much time/mileage does it take
until it becomes catastrophic?
 
Thanks
 
Alfred