850 head

hi i am looking at a 73 850 intestate which looks to have oil staning around the 4 & 5th fin on the head.
i have read some were about a batch of 850s with pouress heads.
how do i determand if this is so. can this be tracked down to build frame and engine numbers.
what problems would there be down the track

Problems down the track?, continuous oil stain, inlet rocker box leak comes out about there as well

Hi, I have seen pictures of the RH4 heads cracking through the centre of the carburetor bolt hole to the plug thread, and the valve seat. I have seen a couple of repaired ones on eBay,not an easy job, as the valve seat can drop out. Be prepared for a new head. Offer a price to allow for this. Best of luck, Paul