I'm looking at doing a comp 268 cam. Has anybody done this? Was there any custom tuning needed or does it run well off a canned tune? Is there a noticeable idle difference and what kind of performance difference did you notice?

 

These aren't comp cams but they should give you an idea.

http://www.youtube.com/watch?v=KFQ1sQ6s2EM

http://www.youtube.com/watch?v=7iBtUPf8GKk

 

I can't say about the Hemi, but I had one in my old 77 F150 with a 460. It had a nice mild lope to it. Made good power too. That would probably be my choice for the Hemi as well.
You will probably need a custom tune to get the most out of it. Says required programmer.
I know Diablosport can write a program for it, perhaps Superchips can as well.

 

Personally, in a heavy QC 4x4, I'd opt for the 260, stronger low end torque cam. The 268 is more of a strong mid & upper rpm cam, better suited for the strip. I'd put the 268 in a reg cab or 2wd model myself.

 

I like the 260 but I want something with a noticeable idle change. The 268 seems like a happy medium and comes in at a better price around here. I just haven't heard of anyone actually doing it on here or anywhere else for that matter...

 

With the 268 you are going to need a custom tune. If you try to run it on something like a canned SC tune it is going to stall when you come to a stop. You might be able to get away with the canned DSP tune and raising the idle but you are still not going to get all the power out of that cam without a tune. For your truck, a qc 4x4 you might want to look at cams with more low end torque bc as hammer stated, the 268 is more of a mid to high rpm cam. While the 268 works great for a 2wd rc, not great for your truck. The HHP 260 is a good low end cam as well as the sidewinder. Either of those can also run on a canned tune without issue which is a nice plus.

 

Do any of those cams have a "lumpy" idle?

 

No, you can tell the difference between the stock idle and the idle with one of the cams I listed but it is not lumpy.

 

The "lumpier" the idle means more loss on low end performance and your engine will need to rev super high to achieve the additional power. if you watched the second video clip, that guys truck is shifting at 6500rpms.
Also, the Lumpier you go, the smaller the power band will be.
The only cam that I would even think of putting in my truck would be a towing cam which would help the low end bog our trucks have and it will retain the upper HP and tq power.
Lumpy=track use.
Mild-no lope = street use.