How about these cam specs

[oleshifty]

Looking at this cam from VHP

DUR @ .004" 272*/280*
DUR @ .050" 210*/218*
LIFT .551/.551
OVERLAP 46*
LSA 116* "ULTRA TORQUE"


POWER RANGE 1500 TO 5800



How noticeable would this be over a stock 5.3 cam (does anyone have stock cam specs...i can't find them)?



The MAIN goal of the truck is to get the best fuel mileage possible at about 70mph (truck is mostly driven on highway) but I have a heavy foot, and occasionally pull a small boat. With the current gears, the truck RARELY sees above 2500rpm. I want the truck to be faster, but am mainly looking for more "passing power" on the highway. As of now, it needs to drop into 2nd gear to get out of it's own way. The top end on the truck is amazing, but it is a real dog below 3000rpm. I may mess around on the street every now and then, but it will never see a track.

With the cam, it will be getting a set of heads (mildly ported/polished set of 243's or equivalent)....some LTs...injectors...a tune

[Botlfed]

191/190 .466/.457 114

[oleshifty]

So it's a decent difference...THANKS


i'd hate to spend the money and not notice anything

[Z'06]

That should be a great cam for a 5.3L and would let you even get away with running a stock torque converter (I'd probably want to match it with a Circle D 278mm upgraded Trailblazer converter at some point; possibly the 2600-2800 for what you are describing). Some PAC 1218 springs would be perfect, although you could possibly still get away with yellow LS6 springs.

Stock cam for the 5.3L is 191/190-.466/.457-114 according to this thread. What's interesting is a guy in that thread (Thunder550) says he used to run that same cam (same specs anyway; possibly Vinci).

That cam with stock heads wouldn't be too noticeable if you weren't listening for a cam (most would think it's your LTs/cats/mufflers changing the tone), but once you add the 243 heads into the mix, you might change the acoustics a bit.

[oleshifty]

My exhaust is dumped right after factory cats now...I'm going to probably have to throw a muffler on it now


Noticeable as in SOUND or power? I can think of better places to spend the 600 if it won't help power.

PAC 1218 springs? Where can I get those? I've heard a lot of talk about comp 918s.... VHP recommended a set of double HD springs (set was $320)...think I'll pass on THAT.

[TXsilverado]

i would drop the LSA down some if it were my truck, but i'm not sure what you are looking for.

[oleshifty]

I was also looking at a

DUR @ .004" 272*/280*
DUR @ .050" 210*/218*
LIFT .551 / .551
OVERLAP 48*
LSA 114*


Basically same cam, less LSA, but he recommended the first one I posted for my application (main difference I see is a 200 RPM drop and little smoother idle)

[Z'06]

Noticeable as in SOUND or power? I can think of better places to spend the 600 if it won't help power.

PAC 1218 springs? Where can I get those? I've heard a lot of talk about comp 918s.... VHP recommended a set of double HD springs (set was $320)...think I'll pass on THAT.

Definitely noticeable as terms of power, but not noticeable in terms of sound with the 116LSA.

Get the PAC 1218 springs here. Comp 918 used to be relabeled PAC 1218 springs (i.e., PAC was Comp's supplier), but then Comp switched production and there were some issues with broken springs from the new production batches. Some say the issues are still occurring. Lots of threads on PT.net discussing this. Anything more (including double springs) would be over-springing and putting unneeded stress on your valvetrain.

I'd get a lower LSA on your lifted truck to help bring the power curve down a bit, especially given that you don't tend to exceed 2500 RPMs stock. If you think a 112 would be too choppy soundwise, the 114 should do the trick for being more aggressive than stock, but not as head-turning as 112.

[oleshifty]

ya, my gears are going in next week, going to wait to place the order on the cam to see what the NEW rpm range is. i know it will be higher, not sure how much. 75mph is about 16-1800 rpm now...it should be closer to 2500-2800 with gear.

[oleshifty]

Are new retainers needed with the springs? I noticed some kits have them, some don't.