I picked up this DT2 disassembled in a box and trying to get it put back together. After putting this DT2 motor back in the frame and trying to install the exhaust, I noticed the pipe is hitting the cylinder head and making the pipe not fit right, then while looking at the illustration on Partzilla, I noticed the spark plug holes are different on a DT2 vs MX. Now Im wondering if the whole top end is MX? Would it matter, other than the pipe rubbing against the cylinder head a little? 

Be good to see pics via an external provider if possible. High comp head on a std cylinder isn't good as squeezes too hard. But I wonder if it's a dt2mx cylinder as well. Which would be somewhat restricted by the std exhaust. Dt2mx head fins sit tall. Dt2mx cylinder has the fins kind of around the exhaust port so shrouding the exhaust fitting by memory. I had one of those bikes new out of the box. That opened up a whole new world lol.

I replaced the head on my RT-1B in 1972 with the MX head. Much compression and ran very well, but have no idea what was going on with the lower end? That motor ran fine up to '75 when I sold the bike.