430 rivie Manifold ?????

[ducenqtr69]

I have a 68 Riviera 430 Cid Stock engine , but am Haven trouble finding the Manifold Casting Numbers It is 1386686-1 AN i also have a 69 430 Electra Stock An the Manifold casting Numbers are 1386003 this is Correct as per the Atlantabuick.com information but this 68 is Strange Because i have to put on a 1/4''+ inch spacer between the Manifold an Carb in order for the Fast idel Cam an Adj Screw to clear the Manifold Surface,any Idea what this Manifold Is ????? the Engine LOOKS stock from factory NO Paint missing from the bolt heads or Gaskets Different all vac Hoses look correct per the Shop Manual, Any Help appreciated , Thanx Thom (Nevada)