The engines 4-9 have the same basic structure cos the block and head is the same shape size just have slight variations regarding internals and bolt ons.
The manifolds are the same so you would just fit the 4/5/6 elbow onto which ever engine you want cos it only the joint where the elbow meets the downpipe that's different between 4/5/6 and 7/8/9 cars. Oh and the downpipe on a 7/8/9 is longer due to the fact the car is longer
Simple elbow swap really. You use the early elbow Frome the early car to match the exhaust to the turbo of the newer car.
Hence why IX turbos are so easy to fit on 4/5/6 models
I have an 8 engine in my 6