I know it has been done before so hopefully the appropriate people can guide me. I am in the process of adapting ITBs from an RB26 to my RB25DET Neo head. I am doing some upgrades so want to do this same time. I have had a go at it and after some more work I am needing some information in regards to the lower intake manifold on the RB25DET/RB25DE/RB20DE Neo heads. Does anyone know if the lower intake manifold of the RB25DET, RB25DE and RB20DE Neo heads are the same? Also how difficult is it to cut the lower runners and make a plate to adapt the ITB setup? I am thinking this will be an easy option and what issues clearance-wise may I encounter, I am thinking the OEM oil cooler setup but I have already upgraded to a Trust external setup, next move would be to relocate the filter as well.