The DTM kit and conversion flywheel bolts right up to a type one transmission.
The DTM turns the T4 into an upright fan, generator and fan used is type 1, it will fit a T4 engine anywhere a T1 engine will go.
Below is a 2056cc, 914 2.0 heads, CSP SS header, 40mm weber IDF's WEB camshaft, T1 pump, full flow oiling and the DTM is the fan shroud. About 130 HP maybe a bit more. Compared to the T1 it's a torque monster, this engine is going into a beetle.
If on low budget a stock type 4 can be used, with 914 2.0 heads and header still give you 100-110hp, stock and fairly bulletproof.
One year only the '76 912 used the T4 engine.