Here's a factory service sheet pic of the porting layout of the RT2MX. Interesting how the rear transfer lower side is way down below the others. Could that be to get a steep upward squirt of the fuel--so steep an exit that it needed to be much lower to avoid running into the top of the transfer exit rather than out into cylinder & combustion chamber. Also the top of the front transfer tapers a mm or so from front to rear. Be great to be a fly on the wall at the factory to see how they decide on all these final decision of porting compared to say the next model year. [can't go previous year as was piston port but anyway]. My RT2MX cylinder i always thought took an RT2/YZ80 reed [i'm sure the holes are the same]. But fitting my cylinder last week i found a new reed block that goes straight in with 6 [three top & bottom] reeds & think it was for an Suzy RGV250. Its in there & running.