4.7 into my LS400

[dirtybrd]

Hey guys, just joined. I'm a long time Toyota/Lexus guy. I have access to a very good used 4.7 and want to swap in the my 4.0 in my 95 LS400. From my understanding there is a mod or two required to do this other than just buying the motor mounts. Can anyone go into more detail about the please?
Thanks in advance,
Chris