They will bolt up, but the ports don't match up correctly and would require quite a bit of grinding/polishing to port everything so it'll match up without having the lip that would restrict airflow.
Direct quote from S-A Designs High Performance HEMI builders Guide pg. 71-72:
some enthusiasts have swapped the 5.7L's composite, long-runner intake with the 6.1L's aluminum manifold, which features shorter runners. But with the 6.1L manifold fits the 5.7L, it is of limited effectivness without additional performance modifications to support its air-flow design. An upgrade to increaded flow cylinder heads, a supercharger, or nitrous-oxide would compliment the 6.1L manifold.
A caveat to using the 6.1L manifold: without proper tuning, the 5.7L's computer won't like it.
Don't know if this helps but I know a quite a bit of chargers and challengers with the 5.7/6.1 manifold swap with "Crank This Motorsports" adapter kit. Never heard of any restrictions or anything.
I found this on ChargerForumz.com that a guy did 5.7 to 6.1 intake manifold swap. He went through this company: http://www.inertiamotorsports.com/motors.html
The upgrade kit is towards the bottom of the page its $425 for the kit and then you have to supply the manifold and do a couple other things like build a CAI for it, but its very possible.
If I remember correctly I think the guys name was Stu at that company.
There is a picture of the engine with the swap but the file is to large for me to post the picture.. If someone else would like to post it here I have the link.
This is the setup the guy used with the swap:
FRI Ported & Polished 6.1L Manifold
FRI 5.7L Extreme Cylinder Heads
FRI Littleboy Camshaft
yeah thats definitely Stu at Inertia. One of my buddies has his 372 stroker motors which is a 5.7 block based motor and he has the the 6.1 manifold on it. Inertia also makes the manifold swap kit for the 4th gen rams with the 5.7. Definitely one of my next mods.
it will take a lot of work to do it and the 6.1 intake was made for the LXs and you will lose bottom end tq and if you have a 2500 w/HEMI you probably don't want that
But then the exhaust ports are different, and you would need the 09+ exhaust manifolds or headers. Trying to retrofit that into a leaf sprung truck may be a bit daunting.
I believe you can get a spacer plate, that bolts to the early 5.7 heads, and then the 6.1L manifold.
Not to hi jack the thread but does anyone know where you can get the specs for their camshafts? looking for the lift on their crazy jay, spartan, and crazy spartan cams.
So once you have a 6.1 manifold w/ your trucks 5.7 TB, would you be able to install the same line of CAI's that the 6.1 LX platform uses? This does not include fitment of the piping. Just hooking it up to the TB.
Used Aria for sure but not new. LMI "Hammer Design" would be my option. Just not sure if there is a difference of fitment due to using the 5.7 Ram TB vs LX TB.
400 is not bad if it includes the injectors and fuel rails. Cost me about 1,500 to do the conversion but would of cost a lot more if i brought new. Little pieces add up but most of it is due to being a pre 09.