any carbies other than the dcoe webers will be expensive to set up and get working properly as jets and chokes etc are getting hard to get for them.
Especially when you are trying to swap them of two very different motors.

38mm is very small, keep in mind the silvertop throttle bodies are 42mm (or are they 40mm- i forget).

You can get a new set of DCOE webers for a little more, you will be able to buy an off the shelf manifold for them and linkages that will actually work well. Plus you can get them setup by someone who will actually know what they are dealing with.