Did anybody try to fit the swing arm from a 1978 YZ125 into the DT frame before? I got the chance to buy a complete YZ125 in parts for cheap. I am already pretty sure the fork will fit. The combination of both would be a very nice suspension upgrade! Also I can get a cylinder from the IT175 from the same guy. It's from the model 77-79 and will definitely fit the DT engine. The ports look really promising! But I would also need to upgrade the intake side... 34mm carburetor, intake manifold with boost bottle port, reed valves, find a solution for the airbox... open air filter is not an option as I want to take the bike out in the dirt.

1978 YZ125 swingarm geometry is different.  Rear shock is too big to fit DT frame.  Front forks will not fit.

1977-79 IT175 cylinder definitely will NOT fit DT cases without fairly extensive welding and machine work done to cases.