This is the TWM B-series ITB kit:



Observe the complete manifold, tb's etc. The intake manifold flanges on B- and D-series motors are different.

However, TWM also makes manifolds to bolt a pair of Weber DCOE carbs to a D-series motor. Like this (thanks for the pic Harry):



Now, you don't want to run carbs on a fuel injected car. Well you could but anyway. TWM also makes two-barrell throttle bodies that are shaped just like DCOE carbs.



So, you want ITBs on a D-series you need a DCOE-style manifold and a pair of TWM fakemeout DCOE throttles.