Part# AS0027 : Ford 302 351 Cleveland quad weber inlet manifold. Suits IDF weber carbies with 90mm centres. Low design suits 2 V heads however there is enough meat in the casting for you to blend it up to 4V heads.

As far a the CHI 3V heads go this manifold will bolt up ok however the CHI port is about 1" higher in the head than a stock Ford port and hence a big miss match.  To get this manifold to fit CHI heads you would need to blend the bottom of the port in the CHI heads and resin fill some of the port floor in this manifold and then open the top of the manifold port up some, so this would need to be done by a competent person. Just note you will have a small port feeding a large head, which is good for street torque and limits reversion but will possibly hinder maximum hp potential in wide open throttle racing aps.

The manifold has a total height from the block end seals to the top of the carburettor pads of around 90mm

As a note the IDF down draft Weber carburetors have venturies that are 90mm apart [90mm centres] which this manifold suits. Their sister carb the IDA down draft weber has 120mm centres [wider apart] and hence does not suit this intake manifold.  As a rule of thumb the IDF carbies are better for street driving becasue the IDF carbies have a better overlapping of the progression curcuit, it has 3 progression holes from factory.  In a nut shell this feature gives you better driveability at part throttle openings which is where 90% of your street driving is done, even if it is only to and from the track days.  Think of the IDA Weber as more of a pure race carby where you are either on the throttle flat out or you are on the brakes, like on a circuit car, with a big race cam.  For most of us the IDF will be the better selection for street, hill climbs and track days, and since the IDFs are smaller than the IDAs they make the whole package smaller, hence why we have a dedicated manifold for the the IDF Weber carburettors.