What modifications do I need to do here?

I know I need to change the intake, but I am looking at the bed plate and the oil filter is in a different spot and the XJ has no oil cooler (mine does)

 

surely I am not the first to attempt this?

 

You are probably not the first, but still a very rare job I'll bet. Be patient - someone will eventually chime in....

 

You may be the first. However, people have done similar ones and posted about them. May take some serious effort to find them. Start with posts by Bob i.e. motorcarman

Also, the engine repair etc courses are on here if you look!