Stock 5.3 head question

[slicks2003]

Whats the max lift the stock heads on our 5.3 can handle?

[PEWTERLIFTEDZ]

are you talking about the actual heads or the springs on the factory heads?
the factory springs can only handle about .500 lift.

[Topspin]

Hey Pewter, I was just updating an old thread of mine with the LM4 pressures. The stock springs are poor, and though they will physically handle mid .500 lifts they have very poor open pressure for high rpm use.

[xoxoxoBruce]

Topspin, you should have told 'em where.

[PEWTERLIFTEDZ]

ya when i threw my baby cam (513/520 lift) in my silverado i switched out the springs to LS6 springs.
the factory springs on the 5.3s are hardly up to the task for factory cams lol.

[Topspin]

Thanks for the link Bruce - I'm too computer challenged to accomplish that!

[slicks2003]

Thanks, I'll have to replace the springs if I do a cam upgrade then.

[slicks2003]

I know this thread is a little old but. did not want to start a new one. Here is the cam I have in mind. I had basically this same cam in my ZZ4 engine that was in my 72 Nova which performed very well (400hp at the rear wheels). I'm good with gen1 engines but, never worked on a gen III except for my header install. Does anyone know were there is a step by step I can review?

Besides the parts below, any thoughts if I should replace the lifters and push rods? The engine only has 13k on it.

Here's the parts I had picked out (LS6 hot cam), I'm just looking for a bit more HP and TQ on the low end.

GM Performance 12480033 - GM Performance Gen 3 Hot Cam Kits - Overview - SummitRacing.com

I was also going to replace the rockers to full rollers and these are 1.7.. Scorpion Performance SCP1098BL - Scorpion LS Race Series Rocker Arms - Overview - SummitRacing.com

[Doug Allen]

I recommend you contact Garth at Leading Edge Performance. I bought my cam from him, as well as many others. The guy is a walking encyclopedia.....

Leading Edge Performance | Site by: F2F Design

[slicks2003]

Originally Posted by Doug Allen

I recommend you contact Garth at Leading Edge Performance. I bought my cam from him, as well as many others. The guy is a walking encyclopedia.....

Leading Edge Performance | Site by: F2F Design

Looks like a cool site, thanks for the info..!

[53wanab]

Hey slicks2003,if you never have changed springs on and engine with the heads still on before,you will need :
1). air compressor
2).Special spark plug adapter hose/tool to apply pressure to cylinder which keeps valves locked in place for spring removal.
3). Special mini valve spring compressor to facilitate spring keeper removal.
Very tight space especially last two cylinders at firewall.
Also,the stock rocker design cradles the assemblies in an aluminum tray that bolts to the head with no adjustment.Check the replacements for same design and you may need to change to shorter/longer push rods to compensate for roller tips.
I installed Comp Cams 1:85-1 roller rockers with hardened push rods .These required discarding the stock assembly and screwing in individual studs with adjustable lock nuts.
P.S. the valve cover required 1/2" spacer to allow clearance even though manufacturer advertized "Fits under stock valve covers no mods."

Sorry to Comp Cams, its' the truth. Love you guys and your products.