Heads?
Jul 7, 2005 | 06:06 AM
#3
Staging Lane
Joined: Jun 2005
Posts: 60
Likes: 0
From: Colonia, NJ
I actually gave this some thought, short of ordering new heads and paying up to $1500 I thought of maybe taking a ride to the local junkyards and pulling some heads off an LS1..send them in for a port/polish, bowl blend, and 5 degree valve job...
Jul 7, 2005 | 06:51 AM
#4
Originally Posted by GMPartsGuy
Anyone got any ideas on a simple head swap for my 2003 GMC 5.3? Just want to bolt off and bolt on a diffrent set for a few more HP!
WCCH has a nice Stage1 for a 5.3 cylinder head.......I'd give Richard from West Coast Racing Cylinder Heads a call as he can give you very good advice.
Here is a link to what I ended up getting:
http://truck.ls1tech.com/forums/show...highlight=WCCH
hope this helps you out some
Jul 7, 2005 | 05:44 PM
#5
TECH Fanatic
Joined: Apr 2003
Posts: 1,107
Likes: 2
From: Albuquerque, NM
Although the GenIII heads are totally interchangeable, the combustion chamber volume varies by quite a bit. The 4.8/5.3 heads have the smallest chambers ( 62cc ) so swapping to the LS1 ( 68cc ), LQ9 ( 72cc ), or LS6 ( 64cc ) will usually result in a loss of power due to the reduced compression ratio.
You also need to be careful of "valve shielding" where the smaller 4.8/5.3 bore size will interfere with the air flow around the valve itself.
Most of the aftermarket head companies start with the truck heads as cores as it is easier to remove material than add it. Allows for the CNC machine to form a better and more even chamber shape.
If you do decide to go with another head stay away from the LQ9 or #317 models. you would need to cut them down or go to an extremely thin gasket. If you go F/I then any of the other head models will work well.
You also need to be careful of "valve shielding" where the smaller 4.8/5.3 bore size will interfere with the air flow around the valve itself.
Most of the aftermarket head companies start with the truck heads as cores as it is easier to remove material than add it. Allows for the CNC machine to form a better and more even chamber shape.
If you do decide to go with another head stay away from the LQ9 or #317 models. you would need to cut them down or go to an extremely thin gasket. If you go F/I then any of the other head models will work well.
Jul 7, 2005 | 07:11 PM
#6
I was actually talking to Richard from West Coast Racing Cylinder Heads as well. They have core ready, once you purchase they will do what you want. Then you unbolt your heads take them down to him and switch em and bingo new heads in a day!
I was considering this as well, bolt after talking with richard and evaluating my 5.3 and towing needs, I might not do the heads and cam.
I was considering this as well, bolt after talking with richard and evaluating my 5.3 and towing needs, I might not do the heads and cam.
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