This topic has come up before. Largely because the first gen 4.7L engine is relatively underpowered. I can say that because I had one in my 2006 QC 4x4. Your truck probably does a little better than mine did considering yours is RC vs QC.
The 4.7 can be modded some but the aftermarket hasn't been as kind to it as the Hemi. For example, unless it has changed since I traded my 4.7 truck, there are no headers available for the 4.7 engine. You can obviously do things like a CAI, tuner, and exhaust. If you really want to get serious I believe there are also some intake and head options. There may or may not be any cam options. The only one I am familiar with is the OEM high output cam swap and according to AirRam's site, these are discontinued and no longer available. Here is the site if you want to check it out.
Given the ground that you need to make up to reach Hemi level (110hp/80tq), the lack of aftermarket support, and the cost that would be involved, I think you are better off with the Hemi. Not to mention, a 4.7 modded to Hemi level is a going to be a relatively heavily modded engine making what a Hemi makes bone stock. I just don't see the value.
Originally Posted by tjbiker031
I dont think you quite realize how involved a swap really is. You need to modify the motor mounts on the frame, get new transmission and maybe drive axle and rear-end, new ecu, new wireing harness and totally rewire your car, and the list goes on.
I don't think it's going to be quite that bad. I don't know about the engine mounts but the transmission and rear end and all the other drivetrain components are the same in the 4.7L and Hemi trucks. Yes, I would assume the PCM and some wiring will have to be swapped. It won't be simple but it's not like stuffing a V8 in a Toyota Camry either. Even so, the cost of the Hemi engine and the associated parts aren't going to be cheap.
I think your best bet is going to be to do what I did. I took care of the 4.7L truck and kept my eyes open and when I found the Hemi truck that I wanted, I traded. Couldn't be happier. Good luck!