[Captainfab]

If it is a typical G series van that is a unibody design, the crossmember is different than for a C series truck. If it has a typical frame as a C series truck does, then the crossmember should be the same. The good news is that I do believe the control arms are the same as the C series as well as the spindles and calipers. However I do know that on the G20 vans, the lower control arm shaft is a wierd looking piece with an outter sleeve with rubber in between. The G30's may be different.

The steering box from a G series van will not work in your '66 C30. Even if you change the pitman arm, the sector shaft turns the opposite of the input shaft.