Seems like a lot of work to replace a really good carburetor with something else, but if you really want to do this, an adapter should not be necessary. Here is the method (assuming that the bolt pattern, and throttle bores of the eclone exactly match those in the intake manifold):
(A) A trip to the local auto parts house
(B) Ask for the black, rubberized gasket paper (would suggest Armstrong N-8090, but there are probably other brands)
(C) Set a piece of the gasket material over the manifold
(D) Using the "peen" of a ballpeen hammer, GENTLY strike the gasket material all around the fuel holes, and bolt holes, making a pattern impression on the underside.
(E) Cut out the gasket to have 8 holes only, the 4 for the air/fuel, and the 4 mounting holes. Your wife or girlfriend"s (not both!) fingernail sissors are good to cut circles.
(F) Install gasket and e-clone.
(G) Begin the adjustment procedure.
If the holes in the e-clone do not exactly match those in the manifold, acquire a 3/8 spacer from the local speed shop. Use the gasket you cut above between the manifold and the spacer, and use the gasket supplied with the e-clone between the spacer and the e-clone.
A better (MOO) suggestion: sell the e-clone to some 16 year-old, and rebuild the original Rochester.
Jon.
