Hay Ruttly
I had a 2004 Sportster 1200R ,
Running with them SAVAGES in the Mountains tore it up (Primary Drive splines on crank went gone) so I swore-off Harleys for a while.
Then in 2007 I got a 883 , well that TALL GEAR of the 1200 had me wanting the same gear on the 883 ... So ... I switched to a 1200 primary set and loved that bike for about 50K miles till it started weeping oil , took almost 4 years !

I came to the Conclusion that HD had make the PERFECT BIKE with the 883 with it's 3" piston. Then they screwed it up by putting those oversize 3.5" pistons on a crank and drive gear made for 3" pistons. IMHO that is.
So I bought a Moto Guzzi ... then another Guzzi ...
.....................
The 1200cc splines came back when I built a heat shield around the area then got the Mig-Welder in one hand and the Dremel Tool with a cut-off disk in the other hand. Two days latter there were "Tapered Splines" where there used to be striped strait splines.
That little 350-J motor RE is making is REALLY - A "TOP OF THE LINE" Product. It's just low in the "HP" department , but there are Mod's for that !