Posted: Sat Jul 16, 2011 1:05 pm
Peter Burgess does not think that all Rover V8 heads will run on lead free...
http://www.mgcars.org.uk/peterburgess/page18.html
http://www.mgcars.org.uk/peterburgess/page18.html
Many many years ago when unleaded was coming in, I was a member of the P6 club. A metallurgist who was also a member tested the hardness of the actual seats on a P6 and concluded they would be fine for normal driving using unleaded, but were borderline for extreme use. Like continuous running at maximum speed. Since the P6 had a top speed of 115 mph plus, not likely a problem in the UK.
So I ran my P6 on 'Super' unleaded for some 5 years before getting my current SD1.
If you were doing a head overhaul, it would make sense to fit the latest seats. If an existing running engine, wait until a failure before changing them. You'll have a long long wait.