jdawg04 4.8

iTrader: (1)

After doing some searching on here it looks like its possible with some machine work. My question is would it be worth spending the money to do the machine work (im on a very tight budget) I have the old heads from my 4.8 and i just would need to pay for the machinig to get done.

What would be the pros/cons of doing something like this. I know this would raise the CR but is there any problems/concerns doing this. Im not planning on FI just the spray and if im not wrong the higher CR wouldnt be a problem with just spray.

The motor is an 04 LQ9.

InchUp

iTrader: (2)

I'm curious, do you have the stock heads off your 6.0L? Are those not 317's? I see your tight budget best spent on milling the 317's down for 10:1 compression or higher, and having the machine shop do the equivalent to a "stage 1" job on the heads. Sell the 4.8/5.3L heads to make back some of your money spent on the machine work.

hirdlej

iTrader: (31)

You know.......... I actually toyed with this idea when building my 6L. I would like to see someone take a 862 casting head and do some heavy porting on it, slap them on a LQ4 and go with a 212/218 or 216/220 cam if you want something a little more aggressive. You would have 11:1 compression, great port flow and superior port velocity! You would have a motor that would be uber responsive everywhere and have a flat torque line up to 5K. If money wasn't a factor I'd yank my 243's off right now and try it myself You would have great engine vacuum, a nice touchy gas pedal and super torque just like a truck needs. I would encourage you to do this.

7845

iTrader: (1)

a combo i worked on was

04 LQ4 home ported 5.3s with 2.0 valves, .040 head gasket, 230/230 cam. compression was around 11.3 and motor ran smooth. had a nice powerband. i think if it had a mans cam it would be a beast. [the cam is from patriot]. this was backed by a
t56 with 373s. no numbers but seat of pants compared to other setups ive done says nice strong runner

jdawg04 4.8

iTrader: (1)

The LQ9 is a long block and yes they are 317s.

Why do i see that some people get the 4.8/5.3 heads worked and others get the 6.0 worked. Is it becuase of application.

I do have both heads and just thinking of some ways to get more power out of the parts I have.

Im not going FI and I had a conversation with a guy who mentioned using the 4.8/5.3 to get the CR up it was a long conversation so alot of details i dont remember but i do remember him thinking using the 4.8 heads were better then the 6.0 for a couple reasons those reasons got lost the more beers i had.

I know the 4.8 heads are not a direct swap and i beleive the 317s are good as they sit for my goals. I just got a little intrigued about getting a little more of a CR.

Inchup,
You think the best bet would stay with the 317s and mill them down just out of curiousity why would someone go with the 4.8 heads over the 317s?

Hirdlej,

I have a 04 LQ9 and my 4.8 with mods in sig that includes comps 212/218 lowlift and ill be using everything i can off of my 4.8.

7845

iTrader: (1)

the 4.8/5.3 flow decent amount using the smaller valves. the 317s out flow them. now you could toss on the 4.8/5.3 heads the 6.0 with no issues and only thing holding you back would be the smaller intake valve.

for me and i had to choose.....i would stay 317s and have milled and do some clean up yourself on them

GMCtrk

iTrader: (27)

I don't see the point. LS6 heads are a much better starting point. Compression with LS6 heads on an LQ9 is 11.1:1

7845

iTrader: (1)

its in what he has to work with.

jdawg04 4.8

iTrader: (1)

Thats what it comes down to the heads will be coming off the 6.0 either way.

So what sounds better getting the 317 worked or the heads from the 4.8 worked or just using the 317 as is.

Would there be more money spent on sending either set of heads to get worked or would the price diff. be min.

Honestly going from a cammed 4.8 to a cammed juiced 6.0 is going to keep a smile on my face for a while so doing head work would just be icing on the cake that i can maybe afford.

So far there 2 members saying they would stay with working the 317s and one saying go for the 4.8 heads for me it seems that i still could raise the CR using the 317s by milling them so why would i even want to use the 4,8 heads can someone give me a simple breakdown of why one might choose to use the those instead of 317s

hirdlej

iTrader: (31)

Before I convince you to use the 4.8L heads...... Why don't you tell me your goals? Street bruiser? Track racer? Dyno queen? All the heads have their place and you need to determine what that "place" is. I see you're an auto truck, what gears are you running? Tire height? Are you willing to step up to a long tube header? Keep the headers you have? Sounds like you want to keep it on a tight budget which is fine. But when seeking out your goal, be realistic. Do you have a quarter mile time in mind? Gas mileage a factor? Want to be able to hang with a certain car? (A camaro SS or GTO is what I had in mind)