With you talking about the 4.7L V8 I'm assuming when you are referring to an H.O version of the 4.7L I'm assuming you are referring the 4.7 you are referring to the second generation of the 4.7L V8. Just to let you know that is kind of a different beast. I know the cylinder heads are different where the 1st generation of the 4.7L version used one plug per cylinder the 2nd generation version used two plugs per cylinder like the 5.7L Hemi. Now, there was an older H.O. version of the based upon the 1st Generation of the 4.7L V8 that first showed up in WJ Jeeps in 2001 or 2002 I think it was and also 2005-2006 in the Dakota R/T. Part of the power increase for the "HO" with that engine was different camshafts and intake manifold (I think). Those require different valve springs and such. They're also used to be a company (no longer around) called KRC Performance that had custom grinds for the 4.7L V8 but, basically all those were was just a Crane version of the 4.7L camshafts.
The HO camshafts yielded fairly decent improvements in a standard run 4.7L V8. The other thing is that is mentioned is the 2008+ plus intake for the 4.7 which has different runners and even better runners than the 4.7L HO intake. The problem is you'll need an expensive adapter for the intake if you plan to run a cable driven throttle body from Air Ram Performance. I'm not sure what else you'll need for the swap but, I know that was the bigger thing. A Superchips Tuner (maybe even a Hemifever) version is another thing that helps I think. The camshafts and intake puts you close to what the newer 4.7L is assuming the standard tune is used on the later 08+ 4.7L V8.
Just going from memory, I think a Superchips Tuner will unlock another 50-55 horsepower from the 2nd generation 4.7L V8. The other thing about the newer 4.7L V8s and I'm not sure if this started around 2005 or so but, the 4.7L went to use an electronic throttle body where the older version still used a cable. Again, going from memory Chrysler at the time used a throttle cable driven throttle body until 2004 that I'm aware. After that I'm not sure. It use to be that you could buy a Fastman Throttle Body for the older 4.7Ls like yours but, I see he no longer offers them. The alternative being that you have a 2001 based engine is to use a 2004 throttle body. I think those might be 68mm where the 2001-2002 is either 62 or 65mm. My point is the last of the cable driven throttle bodies I believe offers the largest size. Again, I'm just going from memory. There used to be Underdrive Pulley for the 4.7L that was good for some power as well made by ASP I believe which again is no longer around.
Anyways, you'll need to figure out the electronics since the 2008 4.7L is a completely different beast compared to the older 2001 version. I hope this helps.
