Depends on how they look when you take them off if they still look good use them but if are planning to do more things with the truck later it would be wise to do springs and retainers at the same time so you do not need to get back in the head again. It really is a goal/personal choice

 

This is what I went with. MANTON Part # D-105-KIT-24v 2003 - 2018 Cummins Manton 24V Valve Spring Kit (D-105-KIT-24V)

 

 

I have heard over 4500rpm. Depends on what you do with the truck and how close you'll be to that though. The retainers aren't that expensive. I would go Manton as well.

 

I guess it would help to lay out my plans. I am looking at getting a DPS add a turbo compound kit, which i believe run at 50-60 PSI. I do not plan on running above the stock RPM.
As far as springs, i am torn between Manton and Hamilton. The pricing between the 2 are very close. here is a full kit, including push rods for $650.
Ohio Diesel Hamilton full kit
Unless someone has a link to better pricing on Hamilton. I am weary of running another companies springs/pushrods, and after searching for pricing the savings are not all that great.
i hope that there will be some good black Friday sales coming up, when i emailed some of the diesel part companies they were not ready to publish what was going to be on sale, and planned on waiting until a couple of days before the 24th.

 

You can trust anything Manton makes. They must have seen a demand for high performance diesel parts. We are very lucky they got into are market. They make parts for Top fuel hemi engines. Just my personal choice for my truck. If your doing valve springs, push rods, you should also look into the 6.7 updated rocker arms. Your rocker arms will have galling from lack of oil to the trunnion. Also some ARP studs well your in there. It all depends on if you going for more hp. I ran 800 hp when spraying nitrous, on all stock parts. Just some ARP Head studs. And with a half as! built trans. That was way back in 2007.

 

I will definitely check the rocker arms when i am replacing the valve springs, and i invested in a set of ARP head studs a long time ago, so I am good there. So far the only issue i am having is pricing on the Manton valve springs/push rods. Everything i am finding is more expensive that what is available from Hamilton when comparing similar specs.