LS3 head Lq9 fun in a truck

[COYBILT]

LS3 heads were ordered today for the GMC, LS3 heads feature sodium filled valves and upgraded springs and are identical to L92 Heads otherwise. The list consist of L92 intake manifold, Nick Williams 92mm TB Ls3 heads and reusing my 214/218 cam, its a good all around truck cam.

I will see what this combo makes for power, I hope it is good. I used to run a 13.98 at 100 flat with the my old combo, Im looking for 13.20 if not faster. This a between stages combo that I have put together, My next set up is put a Magnuson 2300 blower on the truck. BTW, the truck weighs 5100 with me in it and a 1/2 tank



I am saving my Old Lq9 heads for my Lq4 Shortblock. That Lq4 is going in a 65 Lemans convertible for my dad that im going to be rebuilding soon. Its the old motor out of my truck, were giving a second lease on life, as a fun motor and not a work horse.

Port the Lq9 heads and LS2 manifold, 92mm Nick Williams throttle body, 224/230 grind cam on a 114LSA, not sure what i am going to do with the bottom end.
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[6D9]

Good deal man should be a fun nice upgrade! I would love to do a L92 set up one day. You plan on putting it on a chassis dyno???

[COYBILT]

yes I do, will see what she makes.

[camcojb]

I am doing a very similar setup for my new Vega project. LQ9 with CNC ported L92 heads, L92 intake, LS2 dbw throttle body. I am going to try to use a blower cam I have as long as I have piston to valve clearance, I'll know in a couple weeks.

Keep us posted on how it runs............ :thumbsup:

Jody

[dropped72ss]

are the ls3 heads a simple swap on a 06 5.3 ????

[70rs]

are the ls3 heads a simple swap on a 06 5.3 ????

I believe the bore on the 5.3 is too small to run the LS3 heads. Maybe someone else can chime in and confirm that?

[camcojb]

I believe the bore on the 5.3 is too small to run the LS3 heads. Maybe someone else can chime in and confirm that?
yeah, you need a 4" or larger bore for the LS3/L92 heads. I think you can machine the block for valve clearance, but not the way to go.

Jody

[COYBILT]

yeah, you need a 4" or larger bore for the LS3/L92 heads. I think you can machine the block for valve clearance, but not the way to go.

Jody

jody is right, you need a 6.0 other wise you need to do the necessary machine work to the block and even then your going to have a shrouded valve. This is what I have gathered about this swap.