Dynamometer Results & Comparisons - 35rwhp gain from small cam in 5.3 L33

First off, numbers are SAE and smoothed. I tried my best to make this an apples to apples comparison but the dyno was acting up big time and I only got two recorded runs. I was scared to make any more passes due to the issues. I tried to get the fuel exactly the same and didn't get to adjust the timing back to where it was for the first pulls. I was down 2*-3* of timing. The WB02 got messed up on the second recorded run so I don't exactly know that the AFR's matched. But here are the combos and results. All pulls were done in Second gear. Total I gained 35rwhp and 22rwtq. The least I gained was 15/20rw. The cam extended the power band by 500rpm also. The injectors are at 100% at 6,200. I have a graph if someone can post it for me.


258rwhp 277rwtq
06' Silverado 5.3L L33 51,000 miles
3.42 gears
31.7" tires
Summit 2 1/4" cat back
Summit CAI
Home ported TB
NGK TR55's
MSD wires
13.0:1 AFR
25*-27* timing
87 Octane
.98 correction factor

293rwhp 299rwtq
Same as above with 85,000 miles
Comp LSL 215/223 .604/.610 112
918 springs w/ locks and retainers
Comp 7.4 push rods
Custom 4" intake tube (made by me)
Close to 13.0:1 but not sure
23*-25* timing
87 Octane
.95 correction factor

My first pull was 288/294rw with 12.3 AFR. So I leaned it out 5% and made another pull but the WB02 read 14.7 from the beginning to end of the run which makes me think it wasn't working correctly. I was having alot of issues with the dyno for some reason. Turns out the magnet for the rpm pick up was broken and missing. But I got two really clean runs. So I am not sure what the final AFR was but I am pretty sure it was around 12.8-12.9. I usually see .1 change per % of fuel change. But I can't be sure. The truck picked up a solid 5/5 and pulled clean though.

I am doing Cal Speed headers next and then a ported TBSS intake and Ported LS3 TB. Hoping to get 350/320rw when it is all done.

Just wondering, did you go with a small cam for drive ability? Is there a noticeable sound difference?

It is a 5,000 lb 4X4 truck with a 5.3 in it for one. You have to down size 5*-10* for that right off the bat. It also has the stock stall that I don't plan on changing any time soon. So I wasn't looking for a drag car, just a good driver with more tq.

It does have a little lope to it in drive. I don't think you can hear it unless you know what you are listening for.

Can we have an idle vid?

Good numbers but it will be tuff to squeak 350 out of it with headers and a intake. It usually takes another 8-10* of duration to break 350 with a L33.

Good gains. How does your truck drive now? Did you gain power from idle to redline or are you missing a little torque way down low?

Good to know. I was only hoping for 330rw with the cam, exhaust and intake but since it did so well with a choked cam I figured I would get a little more out of the exhaust than the typical 20rw and the ported intake should get me 15-20rw. I think it is better to aim high and be dissapointed than setttle for mediocrity.

I will try to get a clip and the dyno graph uploaded to my snapfish so I can post it. It is really mild.

The truck feels almost the same just driving around. I did alot of spark and fuel tuning though to get every last ounce of drivability out of it. Made a huge difference. Messed with some of the air tables as well to give me the acceleration I wanted. You can tell there is more power at cruise speeds for sure. No more kicking down to pass or going up hills and what not. The converter doesn't even unlock any more. Just pulls from idle to red line. The least it gained on the dyno was 15/20rw from the last cam from hit to quit. The truck drives great and I couldn't be happier with the results. Especially since I really don't have the supporting mods to run a cam. With the LT's, intake, 2,400 stall, and 4.11 gears this thing is going to be perfect. I also got the gas milage back to 15.3 avg after the cam through tuning so I didn't loose anything.

did you consider using the trailblazer torque converter for the i6 engine?

Hadn't heard anything about it. What does it stall to? I had an I6 Trail Blazer.

Good info bro, I'm building a carbed/cammed L33/4speed for my 81 camaro...

I saw a cam on eBay (232/234 .600 112) for 200 bucks but unless I got some cnc that would prob overcam the motor for sure...my main thing with getting the l33 was the high compression, ls6 heads, and most importantly 80 pound weight savings!

I would say it is a little big but it is going in a car and you have a manual trans so it could work out well on the top end. Heads would help for sure. If that is out of the question then just mill yours for some more compression to make up for the DCR loss.

Hadn't heard anything about it. What does it stall to? I had an I6 Trail Blazer.

I think around 2500. Theyre cheap around $200-300. Check out performance truck forums for more info.

Thanks. I just saw a post about them over there. Guy was saying he could get one for $70.

Can we have an idle vid?
x2 Been researching a cam for the burb and this might be one to add to the list of possibilities.

Nothing like having 300whp stock like drive ability and 87 octane!

Nice numbers considering the lack of headers. What type of truck do you have; crew cab, ext cab?

I figured a cam that size would lose some power down low. Had a 216/220 in a 4.8L reg cab with no stall or headers and it was a tad lazy.

x2 Been researching a cam for the burb and this might be one to add to the list of possibilities.

Nothing like having 300whp stock like drive ability and 87 octane!


I am looking for a docile, easy on valvetrain cam that produces good flat torque for my road race car. With a small cam and a better exhaust I think I can make 430 ish rwhp in the LS6 thats in it.

Simple and works. Best combo!

IMO the trailblazer i6 converter is a bad idea. The reason it stalls higher is because it's made for a much lighter vehicle so it slips. Buy a real converter if you go with one.

We have used the TB I6 converter in a lot of low 12 second Silverado SSs in the past and they weight over 5000lbs. No problems with them at all, just can't lock them up at WOT. Just make sure to not get a shotty aftermarket one. I was buying them from GM for about $200 a shot and they always did what we wanted them to do.

They will flash to 2600ish with a cammed 5.3l, and blown 5.3l they will go to 2800.

I have an 06' Z71 Extended cab Regular bed.

The cam was a little lazier down low untill I started messing with the timing and tune. After that was done I am almost getting one mpg more now. I just got the headers and Y-pipe installed today and feels a little lazy now. But I have been driving a 825rwhp Vette for the last few days so anything is going to feel lazy right now. I will get it on the dyno next week and see what's up.

I know I am strange but I really like stock converters. I am not dragging the truck so it isn't a big deal. I have the idle set at 750rpm so there isn't much pull. Then only issue is when it goes into drive it goes from 45-47kpa to 54kpa which isn't allot of vacuum. Everything still works great. If the I6 has the same drivability with a little more stall then it could be worth it. I think you can get a Circle D for a little over 300 though. We will see. I have the stock trans and want to keep as much heat out of it as possible untill I can buy another one. When I replace the trans I am going to change the converter.

This is a mild cam but it has some chop now with the headers. The LSL lobe is pretty harsh on valve train also. I just wanted the most bang for duration and lift I could get. I run LSL lobes in my Vettes so just went with them.

I will go back to the dyno next week to see what the headers are worth. After that will be a ported TBSS intake and Ported LS3 TB. Then an U/D pulley. Finally I am going to pull the heads off. Smooth out the runners and chambers, back cut the valves, and mill them down with a .040 Cometic to get my DCR up. That should get me to the 350/360rw mark. I will be done with this motor then.

Small cams are nice in the 5.3. Have had a small cam in my personal avalanche since 2006.

The Trailblazer converter is the absolute worst converter upgrade out there. Get the Yank restalled stock converter. 10000 times better than the TB converter.

I just figured out that my DCR is way low from that cam. The ICP ABDC @ .050 is 60* on that thing. I checked the cam from my 416 and it was 53* and the cam from my 383 was 49*. Those were considered huge cams for the combo and both had 112 lobe seps. How does thos cam close so late? My DCR is way down around 7.2 with one calculator. It may actually be lower due to the readings I got when I entered my other motors that I know where between 8.5 and 8.8 DCR. So a .040 gasket and milling the heads to 59cc's will be a more porportionate comparison to the stock cam.

Don, how much does having the stock stall re-stalled cost?

Small cams are nice in the 5.3. Have had a small cam in my personal avalanche since 2006.

The Trailblazer converter is the absolute worst converter upgrade out there. Get the Yank restalled stock converter. 10000 times better than the TB converter.

Tell me how that Yank converter is so much better lol, if you lock it at WOT with power it will self destruct. In that regard it is much like the I6 converter I guess. Don't down the I6 converter, it will run high 11s in a SSS pick up.

Been there and done that.

I think you can get a Circle D for a little over 300 though.

The budget Circle D converters are just over 400 shipped. Thats the route I would go. Or a I6 Trailblazer one.

Tell me how that Yank converter is so much better lol, if you lock it at WOT with power it will self destruct. In that regard it is much like the I6 converter I guess. Don't down the I6 converter, it will run high 11s in a SSS pick up.

Been there and done that.

It's a POS. Beleive me. Yes, it stalls and seams like a stall converter. Pulled them out of 3 trucks making 400+rwhp. All of them gained .75-1.2 seconds in the 1/4 taking that crap out while getting better drivability.

PS- you don't lock single disk converters at WOT.

With the exception of very few models, GM locks all truck converters at WOT on stock tunes.

The Trailblazer converter is the absolute worst converter upgrade out there.

I agree 100%.

With the exception of very few models, GM locks all truck converters at WOT on stock tunes.

Yes, they do on the low hp motor's.

Can we get an idle video??????????

Yes, they do on the low hp motor's.

What are you calling a low hp model? They lock them at WOT in 3rd gear on LQ9 6.0L VIN N models.

I will see what I can do about a idle and dyno vid. I am going back to the dyno tomorrow with the newly installed CalSpeed LT's and Y-pipe and see what they were worth.

Comp LSL 215/223 .604/.610 112
918 springs w/ locks and retainers

If that lasts more than 3 months without dropping a valve and destroying your motor, I need you to give me your take on Georgia's lottery numbers for the first week of May. Thanks.

The 918's are good to .625 lift according to Comps web site. Is that not the truth? I have the latest version. If they need to be changed then I will change them. Just got these for free from a buddy that only had 2,000 miles on them. I rarely get on the motor on the street and the only time it sees red line is on the dyno. That should prolong their life. This is my first dealings with a single spring. I have always run duals in the past.