krautwi

Good Morning.

Well, it finally happened...dropped an AFM lifter on the 2011 Sierra. I'm looking to do an AFM delete while keeping VVT (can't have too much low end torque for a towing application). I want to run factory valve springs and not limit the VVT cam phaser, so that's ruled out basically all aftermarket VVT cams. With that, I've narrowed it down to factory GM VVT non-AFM cams to keep the cost to something resembling reasonable. I have an image of the table I put together on the cams below...Factory AFM cam on the left, 3 other options to the right.

My goal is to either equal or gain a little fuel mileage and low-end torque without losing any power at the top end. I'm imagining that the tune it's going to need will help a little on the torque and mileage.

Specific questions:

1. I presume I'll lose some on the top end with the 4.8/5.3 cam due to lower duration and lift...is that correct? Both of those engines with that cam rate out at lower power and torque from the factory than the LC9 I have.
2. I do not plan to do any limiting of the VVT control, so it'll have the full ~52° of movement. Given that the timing can be advanced out quite a ways, I don't want to have the piston marry the valves. How much lift is allowable while preventing interference? I know that the current .481 is OK; it's mostly a question of whether the .500 for the 6.2 cam is OK or not.
3. Will the 6.2 cam gain or cost me anything compared to the 6.0 cam for the 1000-5500 rpm range? I'm expecting the 6.2 cam would yield more power at the top due to better lift and a little more duration, but might cost torque at the bottom because of LSA, lift, and duration.

Texas Speed offers the 6.0 L96 cam as an option in their AFM delete kit, so I'd imagine it's a reasonable choice. I just wanted to see what more knowledgeable folks have to say about those choices before I go and order parts, especially given that my goal isn't to add power at the top, which is what most seem to want to do.

Thanks in advance.

G Atsma

The L9H and L96 cams are nearly identical and will gain power everywhere in the curve. If you are keeping VVT you are good there too. Tune should be close enough.

68Formula

The 6.2L cam swap has been done before with stock phaser: https://www.performancetrucks.net/fo...te-cam-556546/ I think the cam number has been superseded with this one: https://sdparts.com/i-19902861-genui...UaAhOaEALw_wcB but basically the same specs.

krautwi

Thanks for the responses...they were helpful. After checking those out, I went with the 6.0 cam. Being $250 cheaper ended up being the deciding factor. Have a nice evening.