9870 STS feederhouse update

The only thing i have seen is.

The cast slat feederhouse chain was implemented in Model Year 2009 (H09070S730101). A service version of this 91 link chain (AH229908), can be used with all wide body STS combines, but in some cases an offset link will need to be removed from each chain strand to allow proper tensioning.

the chain is the only thing that is retrofitable. to get the new spring tensioner, you would have to replace the whole feeder house frame