To make an ITR P73 intake manifold fit you need to drill holes in it to fit the GSRs P72 head. The Skunk2 intake manifold will fit right up to the GSR head and is very close to the ITR one. You will need an ITR throttle cable latch (not sure if that is what it is called) and an ITR intake since the Skunk2 raises the position of the throttle body.