5.3L cam swap

[biggsteve97]

I have an 03 Z71 Tahoe with the flexfuel 5.3L that I am considering swapping in the GM 345hp 6.0L camshaft I have. I was originaly going to use it in the 6.0L swap I had planned but after tearing into the supposedly good motor found the block to be cracked and the machine shop said it was not repairable. So I now have this cam and I am getting the itch to swap it into my 5.3. Just want to know if I can reuse the stock valve springs and push rods or if not what springs and pushrods do I need for this swap?

[clinebarger]

Install new springs!! The stock springs become weak, Seen too many LS engines break springs at 150,000 to 200,000 miles.

GM ZO6 springs for $4 a piece http://www.summitracing.com/parts/na...9224/overview/

[biggsteve97]

Is there a specific spring I should use or can I use new stock 5.3 springs? What about the pushrods? Aside from maybe replacing them can I use the stock ones?

[clinebarger]

The LS6/LS2 springs in the link work perfect, Below 6,000 the stock push rods are fine, Beyond that...Hardened push rods are a good idea.

[crazy longhorn]

Agree with the springs/pushrods....but have to ask? Will that 6 .0 truck cam show you any more than what you are running? From the read that I have done, it sounds like the truck cams are pretty much the same grind, as well as the LS-1 cam? I opted for the Ls2-6 springs on my stock 5.3 , when the valves were ground & ran the stock pushrods(no plans to spin it over 55-5700, from time to time). If I am off on the cam specs, I am sure somebody will post the info, to help you....Longhorn

[biggsteve97]

Well, I am not 100% sure but my stock 5.3L only pushes out 285hp and the cam I have is for the 345hp 6.0L so I would believe that the cam specs are quite a bit different. I will look for the specs and post them soon.

[biggsteve97]

This is what I have found so far. I need to verify that my cam is actually these specs but the 5.3 and 6.0 cams are different. If this is the case I am not sure for the small difference ibetween the cams I want to go through with the swap now. Maybe I should just get a custom tune done and call it a day.

6.0 LQ9
207/196 int/exh @ 0.05" duration
0.479" / 0.467" int/exh lift
116 LSA


5.3 LM7
190/191 int/exh @ 0.05" duration
0.466" / 0.457" int/exh lift
114 LSA

[orngsikL]

that cam swap wont be noticable. find a used ls6 cam or go custom grind. look into the vinci trucker cam.

[71K20chevy]

Honestly it seems the production cams are not a big enough difference to make the swap worthwhile. There are plenty of companies like Comp and Texas Speed that will have more of what you'd want. And yes, the truck cams are pretty much the same, but they got just a hair bigger in the later years. As mentioned above, it's not a good idea to run any larger than a stock cam with the stock springs. Also another thing to consider, with a big enough cam the base circles are usually a little smaller, sometimes requiring long pushrods. A simple cam swap can easily run up into the $1000 range (assuming you buy new).

Not trying to burst your bubble, but a cam swap is a lot of work (and money) and I'd hate to see you go through that and not have a noticeable difference.

[69gmcc10]

Ls6 cam!

[biggsteve97]

Originally Posted by 71K20chevy

Honestly it seems the production cams are not a big enough difference to make the swap worthwhile. There are plenty of companies like Comp and Texas Speed that will have more of what you'd want. And yes, the truck cams are pretty much the same, but they got just a hair bigger in the later years. As mentioned above, it's not a good idea to run any larger than a stock cam with the stock springs. Also another thing to consider, with a big enough cam the base circles are usually a little smaller, sometimes requiring long pushrods. A simple cam swap can easily run up into the $1000 range (assuming you buy new).

Not trying to burst your bubble, but a cam swap is a lot of work (and money) and I'd hate to see you go through that and not have a noticeable difference.

Well, I already had the cam and the LS6 springs are dirt cheap too. Its not really alot of work on the LS motors to swap the cam, atleast not for me. However, its just for the little bit of difference I am seeing in the cams, the swap will not be worth it. Now what to do with this new cam though? My buddys truck has the 4.8L and it acts like it has a flat lobe or a broken spring in it and if we go in to it he wanted to replace the cam no matter what so maybe Ill just have to give it to him.

[crazy longhorn]

The parts sure are not cheap (new)! I added the LS6 springs , when my heads were done....probably opt for a used Ls6 camshaft, when the time comes? Thanks for the info that you posted Longhorn