Well,

Coming from someone who just went through the same thing, all I can offer is advice but you should be aware of some general guidelines:

1. rough idle - if you want the rough idle, look for an LSA of 110.

2. duration - for trucks, I'd stick with something that has a duration of 224 or LOWER. The higher in duration you go, the more you move the powerband up in the rpms. This also affects PTV clearance (piston to valve).

3. lift - some people love higher duration, lower lift cams. some people love lower duration, higher lift cams. there is a difference in how your truck will run. get what YOU want, not what someone else says you should get.

4. be realistic - meaning, if this is your daily driver, don't over-cam your motor. you won't be happy with how it runs in the end, i promise. a daily driver will perform much better with a lower duration cam over one with a higher duration cam doing the same rpm's.

take me for instance. I spent ALOT of time looking over cam cards, reading posts upon posts upon posts about what to get. In the end, i got what i thought would do well in my daily driver and i have not been disappointed with it one bit. for reference, i'll give you my cam spec's:

218/223 dur .601/.614 lift 112 lsa

this cam performs very well down low and pulls equally as good up top. it has a mild chop, so mild you have to listen carefully for it when it's idling.

as far as the install.

figure about 4-5 hours if you have all the right tools.

 

^^ Great advice there.

Also, call companies like Texas Speed and Comp Cams, go over your goals, truck, and budget, they can point you in the right direction. They sell cams all day long, they know what works, sounds good, etc for various vehicles and goals, give them a call and you'll be happy you did.

 

A 228r Cam from TSP would be a great cam for a 5.3, I'm running it with my LS1 Camaro and it has a great idle and good low end TQ. if your wanting a radical cam with a sick idle i would look at EnglandGreen Cams or Futral motorsports. I ran the EG mayhem II cam in another LS1 car and it pulled like hell. Another thing to take into consideration is when you put such a cam your going to want to up your stall to put the power down at the best time, Springs and pushrods to make sure you dont bust your valvetrain.

The 862 heads on the 5.3s have a 62cc combustion chamber so Piston to valve clearance could be a factor but from my own personal note i ran a cam on a 5.7 with CNC'd 862 heads with the 62cc and a cam with 238/244 620/638 113LSA and i had no problem at all. the 5.3 LM7 and the 5.7 LS1 share the same stroke so i think you should be good in the 600 cam range.

next your going to have to think what kind of cam lobes do you want XE,XE-R ,XFI,LSK.

The more agressive the lobe design the qicker the valve opens and hence the more air/fuel the engine can take in and the more power it will make.

lets say I have a cam with a XFI lobe on the intake(218 duration) and a XE-R lobe on the exhaust(224 duration). The area under the curve on the XFI lobe is greater than that of the XE-R lobe even though it has 6* less duration. The spring life of the XFI lobes will be less than that of the XE lobe. Most people using the XFI lobe change springs after 25/30 K miles to avoid spring failure.

The lope at idle is a function of the overlap the cam has.The more overlap the more the lope(or chopy idle as you call it).You can calculate the overlap from the cam specs using the following formula:

OL = Intake Duration + Exhaust Duration/2 - 2* lobe seperation angle(LSA). A overlap value of -10* will give you a almost stock idle. A value of 0* will give you the chopy idle you like.

Lets take the popular 224/224 cam.Puting these values in the formula using a 114 LSA we get:

224=224/2- 2* 114 = 224-228 = -4. This will give a very mild chop and is a very popular cam with the A4 cars.

If we use a 112* LSA we get:

224-224 = 0. This will give a very good chop

 

Thank you im defiantly looking into it. I noticed with comp that there are normally five levels of cams and the stage three is something I would be interested in any ideas if that would work?

 

One thing to remember is the "rough idle" is because the cam is designed to work better at higher RPMs. You need to set a particular goal for performance, how you want the truck to perform. Low end torque, wider powerband in the middle, or high RPM performance, and then accept that any of the extremes come at a price. A cam designed for high RPM performance is going to be difficult to drive in traffic for instance, and may require other changes like gearing.