The 2.4 CIS heads are unique. These engines had the CIS injectors mounting in the cylinder heads vs manifolds on later engines. The intake ports are also very small. That said they can be used. You can remove the injector bungs in the head and then tap them for threads and screw in plugs to block them off. Alternatively you could have them welded up. Then you can machine for MFI injectors. You will want to bore the ports out to match the larger 2.7 port size. You will also want to change out the pistons so you can use once that match the MFI cams you will want to run. So a little work but not impossible. The thread below show dyno results from a couple engines I built. The last used 2.4 CIS heads.
https://forums.pelicanparts.com/porsche-911-technical-forum/1151593-dyno-summary-testing-early-2-4l-2-5l.html
john