I believe the Flash .12 has the same dimensions of parts.
mmmm ..no the Flash has a different rod so different internal lenghts.
I had 2 of this engines and they worked very well. The price is now less only because of the upcoming of new engines but the quality is ok the same
The last 353 '08 by Novarossi also comes out with the milling needed to mount the engine on the Xray NT1 (I'm talking about the place needed to fix the screws on the 2 alu engine mounts) ..so you just have to build the clutch and enjoy it!
The pipe also works well. The 2652 already has the new conical tube (different from the old 2630).
I gave the last engine (with only 3 litres fuel on) to a friend and after he used it for some more time he changed out the rod and no difficulty on finding it.