What's the difference between the MDS 6.4 cam and non MDS 6.4 cam? I have a friend who is wanting to buy a 6.4 cam to put in his '10 Ram w/a 5.7, and he has the choice between one that is out of an MDS engine and one out of a non MDS engine. Do any of the Gen III experts here know?

If I recall correctly, the MDS cams for the 6.4 use slightly different lobes on the MDS cylinders hence the different part numbers.

If your friend wants to keep the MDS function, get the MDS cam. Makes the swap a lot simpler.

If he does not want to use the MDS, he will need to replace the mds lifters with non-mds ones and have mds turned off in the ECM. This may require head bolts and head gaskets along with lifters and non-MDS lifter yokes(retainers.

If it was me, I would just use the MDS version and be done with it. Either way, the ECM will need to be tuned. IT is suggested that the Comp Cams Phaser Limiter be used as well. But people have not used it and had no problems with Piston to valve clearance.

In all reality that cam swap is only worth about 30-50hp at the crank depending on who you believe. And you may not even see that kind of gain with stock exhaust.

Hope this helps.

Thanks for the info guys. He'll probably go with the MDS cam cause he may want to keep it. Only 30-50 HP increase? That seems like a decent increase to me. I know that an aftermarket cam could provide more but those cams alone are over $800 vs $80-$100 for a 6.4 cam. He drives his truck alot and I personally believe in putting some stock in the durability of OEM cams, not saying that the aftermarket ones aren't reliable, just untested. BTW, the truck has a Predator, MBRP exhaust, and will get headers at the time of cam change. Even relatively stock this thing has ridiculous power for a 4x4 quad cab

My source shows 2012 LC 6.4 specs
591 int
559 ex
286 int
288 ex