Yeah the RB engines tend to last and last too.

One thing I just remembered about the S7. I remember reading on the RB forums that the conrod in the S7 isn't the same "competition" type that is used in the WS7 and WS7II. The advice given on the RB Forums was to upgrade the conrod to the competition type after "5 liters" of fuel. I think that's a little silly, but if that engine has 2-3 gallons of fuel on it, you should do the conrod upgrade. A broken conrod will ruin your day in a heatbeat (not to mention kill a good piston/sleeve assembly).

Another think about changing the conrod. During break in the conrod stretches so if you slap a new one in there and go balls out, it wont stretch properly again and the engine will act weird and the conrod won't last as long. If you change any engine components, it's wise to do a "mini break-in".

Anyway, just stuff I've heard,
-RobH