The 7001-DP is lower than the 5165. The 7001-DP was designed to clear the low hood/bonnet on some of the applications that use the 215 Rover V8 engine.
The 6019-DP manifold is designed to be heated by the exhaust manifold (same as the original Ford design). The intake should be attached to the exhaust manifold at the “hole” you are referring to in your question. A water plate can be used to provide heat...
Thanks for the question. There has been talk about doing a production run of the 2.6L dual port. Although the 6115-DP is a limited manifold for the U.S. market, we understand that it is more common outside the U.S. and that is why we are considering a production...