tallhoedude

i am building a 2004 lq4 from a silverado,can i swap in the rods and pistons from an lq9 motor?if so and use the stock heads,what kind of c.r. will that build?
anything else to think about with that swap?
thanks
andy

ss.slp.ls1

iTrader: (36)

If you swapped over rods & pistons from a LQ9 into a LQ4, you would then have a LQ9. With the 317 heads, it would have the CR of a stock LQ9 which is 10.08:1. The LQ9 was rated from the factory as 345hp/380tq. Without swapping pistons, you can achieve the same CR by bolting on a set of stock LS6 (243) heads onto a LQ4.
As long as you are building the block, I would bolt on a LS6 intake and slide in a nice cam with some quality springs. Also the LQ4 80mm cable driven TB should bolt right up to the LS6 intake, its better than the stock LS1 75mm TB's.

tallhoedude

thanks for the help.
i have read that the newer lq9 rods were better,stronger.
would it be worth the swap?i work at a gm dealer,so i can get them for a steal$.
i am for sure changing cam and valvetrain,need to figure on which heads to run still.
this is going into my k5 with 2.5 ton running gear and
50"+ tractor tires,so im gonna need torque and low end power,would the ls1 intake be robbing me of low end?

ss.slp.ls1

iTrader: (36)

I don't think LS1 will rob you of torque, I think its in the upper RPM's where it is outshined by the LS6 intake. Actually the truck intakes are made for torque and perform very well (comparable to the LS6 intake from what I have read) up until around 4500 rpms where the hp falls off some. But you won't go wrong with a LS6 intake if you've got the money, it's a very well designed piece.
For a torque, I might consider putting in a TR224 cam into a 6.0, along with some quality springs.

My goal long ago was to build a LQ4:
stock bottom end
LS6 (243) heads (milled to yield 10.5-11.0:1 CR)
LS6 intake
SLP lid (use in a fbody, a nice CAI for a truck will work)
LQ4 80mm TB
TR224 cam
1218 springs
chromemoly pr's
LT headers
The above should make for a nice torque monster.

tallhoedude

GREAT!
thanks for the help.
with the gearing ive got im really trying to shoot for between 425-450 on hp and tq numbers.and still live on pump gas.

what if there was a posibility of nitrous down the road?anything to change with the basic build up?
thanks again

ss.slp.ls1

iTrader: (36)

Not really, just add a Walbro 255lph pump and the set up I listed should respond well to nitrous.

tallhoedude

already runnin the walpro pump setup..
thanks for the gameplan and help

tallhoedude

would the truck 6.0 intake or 5.3 intake be best if i need to use a stock intake?

if its the 6.0 intake,can i swap over my returnless line setup from my 5.3?

thanks
andy

ss.slp.ls1

iTrader: (36)

AFAIK, the 5.3's & the 6.0's should have identical intake manifolds. The truck intake manifolds are good for what they are, they will make good power/tq down low and fall off some on the top end. You did say you wanted it to be a low-end torque engine.
If you had the money, I would go with the LS6 intake, not only does it look a thousand times better, but it would probably make similar power down low with no lop off at higher rpms. then you'd have to find the answer to what kind of fuel lines to run. The swap/conversion section should have the answer to that.

tallhoedude

my 5.3 and 6.0 truck engine manifolds are visually quite different.io cant do pics right now.sorry.

my 5.3 intake looks like the typical ls intake,rounded top,can see the runners.
my 6.0 intake is taller,more square and boxy looking????

i do want it to be more low end power,i was just thinking an intake swap could be a future upgrade,gonna have enough$$ in the build as it is.
thanks

ss.slp.ls1

iTrader: (36)

The 6.0 intake is what I was referring to when I was talking about the truck intakes. You should try to find the part number on the 5.3 intake, it will be in the middle of the passenger side. Regardless, I would keep that intake on it because it already has the fuel lines that you need hooked up to it.