07+ 5.3 Cam Swap

NCcummins

NCcummins

NADEAU
Joined
Oct 31, 2007
Location
Asheville, NC
I have a 2007 Chevrolet (new body style) 1500 with the 5.3 in it. It dropped a lifter due to the DOD/AFM right at 130,000 miles. Has anyone else with the newer LS motors done a cam swap and/or a DOD/AFM delete? My truck is currently in the process of having this done. It's not an easy task trying to find every part needed but so far this is what I have:

The following from Comp Cams:

XR275HR-12 222/224 cam:
http://www.compperformancegroupstor...Code=CC&Product_Code=54-426-11&Category_Code=


High Performace LS1 Valve Springs:
http://www.compperformancegroupstor..._Code=CC&Product_Code=26918-16&Category_Code=


5/16 7.400 Magnum Push Rods:
http://www.compperformancegroupstor...e_Code=CC&Product_Code=7638-16&Category_Code=


Hydraulic Roller Lifters:
http://www.compperformancegroupstor...re_Code=CC&Product_Code=850-16&Category_Code=

3-bolt Timing Chain Set:
http://www.compperformancegroupstor...re_Code=CC&Product_Code=3172KT&Category_Code=

We have the plate to block off the AFM. It pretty much just replaces the AFM plate and blocks the plug holes. We are also replacing the oil pump while we can since it has 130,000 on it.

Hopefully, this is all I need to finish this. After it is put back together, it will be getting dyno tuned in order to correct the computer and electronically delete the DOD/AFM.

If anyone else has done this, please let me know what else I need or what route you took.

Thanks!
 
I'd probably run PAC springs instead of Comp 918s. They've had a very troubled past. They might be fine now, but I didn't want to chance it. I've got a custom cut Comp cam and Comp pushrods though. Their lifters are probably fine...I was going to say you don't need to replace the lifters, but since you dropped one, it'd probably be a good idea :D Pro Gear makes a very good timing set for the LS based motors, cheaper too. PAC (most likely PN 1519) aren't cheaper, but it's not something that would deter me. Also, not sure if you have the heads off or not, but I would measure for the proper pushrod length. Measure, add about .030-.040", and that's the length you need. It may very well wind up being a stock 7.4", but I would double check it to be absolutely sure. It's a small mistake that could cost you big in performance or longevity.

Don't forget you'll also need valve locks, valve stem seals, and valve seats. I'm racking my brain for anything else you might need. I just built a high compression LQ4 for my 99 Silverado not long ago, but I forget stuff...you ever forget? Happens to me!

The specs on the cam aren't bad. What always disappoints me with Comp is their durations and lift with be good, then they'll make the cam fall on its face with the LSA. 222/224, .566/.568, 112 LSA...blah. If they'd tighten up the LSA on that one, it'd probably be a whole different animal. It'll have a healthy sound to it. Not a bad cam at all, probably need a stall converter for it though or else it won't be much off the line. If I'm not mistaken, GM Performance Parts makes one with the same specs on a 110 LSA. You'd certainly want some headers if you don't already have some.


I'm just waiting on injectors and a final dyno tune on mine. I'm anxious to see what kind of power it's putting out, mostly interested to see the torque :D If you have any other questions, feel free to ask. If I can't answer them, I'll get you the number of a guy who can set you straight.
 
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I will second Croatan on the valve spring choice. I've seen too many 918's snap and drop a valve. The PACs are good, as are PRC, and the comp duals. Also wait until assembled and measure for push-rod length, 7.4's will probably be right, but you need to measure.

You do need to replace the lifters though, if you are doing DOD delete then there is no need for the DOD lifters and they have been known to cause problems (which you obviously know). The comps will be fine, as would standard LS7 lifters (or comp/morel link bars if you want to get fancy).

If you plan on winding the motor up and want a real lopy cam sound then go with a tighter LSA, but the 112 puts your overlap at 1 degree positive which should work out pretty well for the little 5.3, maybe even widen it out a bit to get a little more low end (you would trade off for less top end).

Oil pump is never a bad idea.
 
Thank you both for the information! I'll definitely make sure the push rod length gets measured. I'm glad you said that, because I wouldn't have. All the parts are here, and hopefully it will be done by mid week. My headers and y-pipe should be here Tuesday morning. I did not have close to enough money to buy nice, name brand headers, so I went with Pace Setter.

The Y-pipe:

http://pacesetterexhaust.com/off-road-y-pipe-07-09-silverado-sierra-use-with-70-2267-72c2267.aspx

The headers:

http://pacesetterexhaust.com/07-09-silverado-sierra-1500-tahoe-long-tube-headers.aspx

I'm also going to delete my cats. It will be tuned as soon as I get everything together and it is done.

Thanks again!
 
Wish I could run longtubes, had to go with a shorty. The SAS didn't give me any room. The key with these motors is letting them breath!
 
Croatan_Kid said:
Wish I could run longtubes, had to go with a shorty. The SAS didn't give me any room. The key with these motors is letting them breath!
Click to expand...

That's what I hear. This is the first gas motor I've had in a long time, so it's all a learning process to me again. I'm used to the Cummins, so the 5.3 is a totally different world to me.
 
These are my second favorite engines to work on with a 12 valve being first. :D
 
That's good to know. I have all the parts now with the headers and y-pipe showing up juts before 6pm. Therefore, hopefully it will be running by tomorrow or Wednesday and it will be tuned on Thursday or Friday. Cannot wait to have the truck back as this has been about a three-four week project.
 
The Dyno Sheet (the truck is currently listed for sale in the "vehicles for sale" section):

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