[2500ak]

Interesting cam 6.0, I've never seen those durations. 113 with a 222/228. That would flow really well, good bit of exhaust bias.

I think that with 4.56 gears a cam might get you a fair amount of mpg's back. This is an interesting case.

Its a LQ9, in a 1/2 ton. The LQ9 has high compression and can stomach a pretty big cam, plenty of excess compression to bleed off.

The 4L65e has a very low first gear, that combined with the rear gears means any low end loss will be minimal. And it takes less power to turn than the 4L80e.

The general rule of thumb for these engines is to have int/ext durations around 220/220.

The LSA will determine the driveability more than anything.

The stock cam is a POS, because its designed for emissions. Wide LSA and low durations what a boring and pointless combination.

Now if the lsa is left wide, you can increase the durations with no loss of drive ability but the midrange doesn't get much more aggressive.

With a closer LSA, and lower durations the engine will yank in the midrange but run out of breath up top.

The stock cam you have is a little better than the usual GenIII truck cam, assuming you have an LQ9 (you have a 4L65e so I'm assuming you do), 196/201 int/ext on a 116 LSA.

Now A healthy cam for this truck would be like a

220/220 with 115 degrees lobe sep.

Or a 212/218 on a 114.

Or the LPE GT2-3 cam. Which is a 204/218 on a 118.5 LSA.

Even the tr cheatTR cam with a 117 LSA and 214/230 specs would be nice.

These kinds of cams won't lope noticeably They are kind of what the truck should have come with from the factory. Healthy cam's.


Anyways, more aggressive mild grinds are like the tr 220/220 on a 112, that's a classic grind, its ubiquitous. Then the 224/224 is a step up from that.

What size tires are you running? Sounds like you have a good candidate for a cam, even without a high stall a light truck with a light trans, a lot of compression, a low 1st gear and final drive ratios should not be that much of a problem.