Got my 2013 GMC Sierra (RCSB) with 6.0 swap tuned on the dyno yesterday and figured folks here might be interested to see what a Gen IV6.0 swap and baby stage 1 truck cam would do.

Originally a stock 4.8/4L60e combo with 50K miles on the engine/trans. Bone stock setup with just a 3.5" custom catback (stock triple catted y-pipe and exhaust manifolds), it made 259whp on 87 octane on a Dynojet in 2nd gear on the shitty factory tune.




Once I got my baseline, I pulled out the 4.8 and swapped in a freshly rebuilt 6.0 L98. Bone stock engine with just a Summit 209/217 cam (SUM-8719) and GM LS6 springs. Everything else remained the same, made 355whp on 87 octane in 2nd gear after tuning.

 

Cool. Thanks for sharing, should make for a nice DD setup.

 

Absolutely. Its such a pleasure to drive with power on tap. The small cam was very easy to tune and drives/idles/feels like stock, just more power.

 

I have the same stock setup and am considering going this route, only with a touch larger cam and long tubes. Thanks for the info.

 

Small cams have been a hot topic lately this is a perfect example of a good daily driver with some power.

got an idle video to show how it sounds?

 

Decent numbers for sure. But I do need to ask, why 87 octane?

It seems mid grade 89 or 91 would be a safer fuel to use on a cammed engine and could allow for a little more power. To me it's more peace of mind to run a little better fuel.

 

Any mpg comparisons between the 2 motors yet?

 

Agree, you can run more timing which gives you more power everywhere, and an increase in fuel mileage. Running higher octane really is an all around win. And it feels so much better with the additional throttle response and power.

If you do the math, you'll usually find that running 93 over 87 is gonna cost you about $5 a month additional if even that.

 

I had a full tank of 87 octane when I went in for the tune so that's what we ended up tuning on. Plus it's a closer comparison I guess. I'm switching to 91 soon and will prolly retune for it. Where I live the price jump from 87 to 91 is minor, but 93 is huge. It's about 6 cents extra per liter for 91 and another 20 cents for 93.

As for MPGs I never really looked at the figures before the swap to be honest. Whatever MPG gains / losses don't matter much to me. I will say though that I rarely drop down from 4th to 3rd like I always did when passing on the highway. Acceleration is now effortless in 4th. So that might account for some MPG gains in the long run I guess.

 

Ah gotcha. I can understand that for sure.

When you go to tune it on higher grade fuel make sure you run 2 tanks of high octane through before tuning to make sure all the 87 is out. Run the 87 real low then fill all the way up and repeat. Should be quite a bit more fun on 87 vs 91

And yeah, you may get better mpg with the big motor since it strains less, a straining motor uses a lot of fuel