SIK02SS

iTrader: (11)

without doing a search i couldnt tell you. Everything is stock, so my guess is 3.73s and either a 245/75-16 or a 265/70-16..it's a Z71, so whichever it uses

wheels may be changed to a newer GM SUV wheel..probably in a 20" size since they are so cheap now. but i probably won't do that until next summer (if that..)

SIK02SS

iTrader: (11)

ok cool...after reading up on them a little more thats kinda what i was thinking too, thanks!

ap2002

iTrader: (8)

i wouldnt go smaller than a 212/218, but definately get it on atleast a 114lsa, it bring get you to the powerband sooner than on a 115lsa...

i used to have that 212/218 114lsa in my ext.cab z71 and did not loose any lowend..

IMO... anything smaller than a 212/218 wont be worth it...

viciousknid

iTrader: (8)

On my 216/220 I lost enough Low End that I can't do a burnout any more. Stock cam would smoke the 20"s from a stop.
Also he has a Tahoe, so there's a weight factor.

InchUp

iTrader: (2)

The Tahoe stays in the upper RPM band when towing up steep inclines because it lacks the low end torque to stay in gear, therefore asking the transmission for help by downshifting to 2nd or 3rd. If it's a daily driver that tows 2 tons a couple times a year, low durations, low lifts and tight lobe separation angles are what you're after. In a 5.3L that XR259 is just the ticket. The XR265 low lift version on a 114 (not the high lift version on a 115) would be the "biggest" cam I'd shove in there.

Remember, dyno tests have proven with a simple LS6 cam, the 5.3L loses torque down low and does not regain that torque it lost until after 2500-3000rpms. The LS6 cam is only a hair bigger than the XR259, but instead it's made for racing and high horsepower in the 5.7L. The XR259 is a mild version of that LS6 cam except with less lift, and as you found out, on a 112. Therefore what you are doing to the motor is basically taking it's powerful low end and only stretching it out, so the low end grunt does not die off until after 5500-6000 unlike the stock cam which wimpers out around 4500-5000. You can only stretch that flat torque curve out so far until you begin stealing from the low end to give to the high end. What's nice about the XR259 is that it will stretch out that RPM band AND increase the torque output while doing so.

SIK02SS

iTrader: (11)

so what you're saying is choosing a cam with the low end power will prevent it from doing the hard downshifts into the upper rpm's, which will then alleviate the added stress put on the transmission? i think thats what i'm understanding...which makes sense

would then the 265 on a 114 take away too much low end in that case? or is it one of those things that its maybe/maybe not?

SIK02SS

iTrader: (11)

if only it was an LQ4 and AWD...or hell, an LQ9 and AWD

i made the mistake of towing the boat with my friends Denali, god damn that was nice to tow with

ap2002

iTrader: (8)

you will NOT loose low end with the 265, i have experienced that cam on my z71....... it gave it enough power in the lowend to do a burnout, when before it wouldnt even try to scratch the tires.... so with that said, a stock converter is what 1500rpm? im pretty sure the 212/218 was already making power at 1500 so that it could burn the tires which were 16x10's on 285's... plus it will give you plenty of mid/top power as well... i had alot of fun with that cam when i had my z71......

zippy

Low end torque from a bigger cam will only come with good tuning. The cam for example in my truck not tuned in correctly would be a dog off the bottom. My dyno sheet show's my torque all the way down to 2700rpm. Anything really lower than that isn't related to wide open which is how dyno runs are performed. I would say go for a cam like the Trick Flow which is:

TFS-30602001
216/220 .560/.560 114LSA

InchUp

iTrader: (2)

You got it.

The low lift Comp XR265 would be a decent choice. Just make sure the tune is spot on, like Zippy said. Keep in mind though that tuning, as helpful as a tool it is, can only give you so much slack. That Trick Flow cam Zippy posted up would be the absolute biggest cam I'd consider in a towing truck 5.3L but your tune must be dialed in perfectly. I fear, even given to the best tuner around, that the 216/220 would still feel like a stock 4.8L right off idle, especially with that 4 link rear Tahoe suspension which is remarkably better at planting the tires than leaf springs. With 3.73's and stock 31.6" tires, I do not see you being able to spin the tires anymore unless doing so in the rain.

Consider the following. I had a 218/224 on a 112 LSA custom ground for a 6.0L LQ4 awhile back that went into a lifted 1500HD Sierra. It hauls heavy loads on a daily basis and is towing large side entry horse trailers every few weeks to various parts of MN and WI for shows. The Sierra has 4.10's and an 80E transmission and can burn its tall tires in 4wd on cement in the garage. There's just that much torque on tap it can do that. Now remember what we're comparing here. A 6.0L to a 5.3L. There's an 11% difference in displacement. That should hint to you, SIK02SS, that what you're looking for is a cam proportionally sized for the 5.3L. Let math and sound reasoning be your guide when picking camshafts.