A set of D3ZE heads for sale in Ontario

[detritusmaximus]

The phase out of leaded gasoline didn't start until 1976, so it's likely you have unhardened seats.

I think I may be conflating  that info on Fords and Opels. Opel began using induction hardened seats in 72. Word of warning, don't get interested in more than one car make at a time...

 

[c9zx]

Easy mistake to make. I had a 1967 Opel Record station wagon when I was stationed in Germany in the middle 70s. I had to rebuild the engine (broke a piston skirt). It ran great after that. I think it was a 1.9L 5 speed manual. Chuck

 

[Stanglover]

Well, I've been trying to get more info out of this guy, but going nowhere. I'm certainly not interested in them nor chasing for more info, so I'm closing this post.