I was doing research for a friend with an '08 Ram 4.7 and ran across this subject;
I found a couple of comments in the 3rd Gen Ram section that adding the 08+ intake to the '04-07 4.7 makes a big difference in power on the earlier engine. The swap requires an Airram adapter to mount the early cable actuated TB to the '08 intake that came fly-by-wire. The intake is around $325 and the the adapter is $270 so that's a $600+ mod! Anyone here know about this or try it?

I also read that the intake manifold from an '02 4.7 HO motor would swap and make an improvement. Anyone here know about this or try it? I looked this manifold up and it's almost $500, so I suspect it's aluminum, vs. the plastic on later versions.

 

been on airrams page, seen the intake and am interested in the swap. common sence would dictate that tith later models that changes to intakes and such would be better than older models, im trying to find some more info on it, if i do ill send u it and would appreciate it if you did the same for me. if one of us dose the swap we should let the other know to get word across as to performance and any issues run into

 

Did some more reading and it appears that all the extra horsepower in the 2008+ 4.7 is from 4500rpm and up; That's not where I run mine so I'll pass on the modification.

I also found some comments that the '02 HO intake manifold (also plastic) is an improvement (also on top end) but not as much as the 2008+

What I like about the Doug Thorley shorty headers is that it gives a big boost down low, between 2000 and 3000rpm.

http://dougthorleyheaders.com/view.j...400.THY121.BMP

 

Bad thing is, Doug Thorley no longer makes headers for our trucks.

 

I had an order in when they announced they were clearanceing them, the rep on the phone told me the order before mine was the last set.