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advice on engine mods

slt5.3z71
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slt5.3z71 Enthusiast

slt5.3z71

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I have my 2004 GMC 5.3 scheduled 10/05/20 for a cam swap and beehive springs. Also adding aftermarket intake and filter, water pump and thermostat. After the engine work my builder will put a tune in it. It has a 3.73 rear end and 265/70R17 tires.

I wanted more torque and my engine builder advises me that I do not need to alter the stock exhaust. No cat delete or even cat back system advised. The new camshaft grind is 112+2 lsa, .523/.524 Lift. 218/227.

What do you think?

Edited by slt5.3z71
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CamGTP Senior Enthusiast

CamGTP

Posted
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He is right in a way. The stock 6.0 makes more power than your stock 5.3 with stock exhaust manifolds etc etc.

 

The mods you have are going to let it make around stock 6.0 numbers give or take a little. Adding long tube headers will pick up some power and also shift the power band up higher in the rev range.

 

The LM7 in 2004 made 295hp/335tq and the LQ4 was roughly 330-340hp and 360-380ft lbs of torque. (crank hp numbers here)

 

I'd say on a good tune with 25-27 degrees of timing with a safe mid 12's air fuel ratio you could get around 310-320hp and 330ish ft lbs at the rear wheels.

slt5.3z71 Enthusiast

slt5.3z71

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Thanks for your reply Cameron.

On another note it seems to me that this is a dying forum. Looking for another  GMC/Chevy forum  with more active participation.

riverbanks Senior Enthusiast

riverbanks

Posted
Posted

How is this site dying?you have a engine builder/tuner,do you doubt that shop also?lots of people here giving free advise, when they can,a bit of philanthropy,all hidden from the media, bummer,no heroes here

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