NemeSS

iTrader: (123)

the 6.0 lq4 vortec pistons replacement are like 400$ with rings
they are speed pro brand, come with grafal coated skirts, 1.5/1.5/3.0mm like stock are pressed to stock rods.
i have used these pistons a few times with no issues, as much as 575rwhp with spray. in a fbody with t56 trans. milled 241 heads, 230 cam, arp rod bolts
they are available in .03-.06 over bores.
come with around 8-10cc spherical dish

skyhighsami

iTrader: (8)

I didn't think you could bore the iron blocks .060

skyhighsami

iTrader: (8)

I had the motor checked and I can hone it. So I am looking for some cheap pistons and rods. I would prefer the LQ9 pistons so I won't have to mill the heads

skyhighsami

iTrader: (8)

Are the LS2 pistons and LQ9 pistons the same? I know the LQ4 has dished pistons but if the Ls2 pistons are the same then I could get some and have a flat top and the added CR without the heads being milled alot

dirt track racer 81

iTrader: (45)

the ls2 and lq9 are the same heres some pistons on ebay i found http://cgi.ebay.com/ebaymotors/PROBE...1%7C240%3A1318

dirt track racer 81

iTrader: (45)

or these http://cgi.ebay.com/ebaymotors/MAHLE...1%7C240%3A1318

1FastBrick

iTrader: (17)

Damn Search really sucks lately but I finally found the chart I was looking for On the LS1Tech side and tweaked it a little...
https://ls1tech.com/forums/new-ls1-o...casting-s.html

ALL Gen III heads are interchangable. How ever They need to mached up with the proper engine combo to see any gains.


Here is a list of a few casting #'s:

933 97 aluminum perimeter bolt 5.7
806 97-98 aluminum perimeter bolt 5.7
853 99-00 aluminum center bolt 5.7
241 01-03 aluminum center bolt 5.7 (some late MY00 cars got 241 castings)
243 04 up LS6 aluminum center bolt 5.7 ***These castings were also used around 05 in truck applications***
862 99 and up 4.8-5.3 Truck heads
706 99 and up 4.8-5.3 Truck heads
799 05 and up 4.8-5.3Truck heads ***reportedly came on a few corvette's too*** These are basically 243 Heads
873 99-00 LQ4 6.0 Iron center bolt heads
317 01 and up LQ4 and LQ9 6.0 aluminum center bolt heads
035 01 - 04 LQ9 6.0 aluminum center bolt heads

Even more info:

Casting Numbers 241, 806, 853
Head: 1997+ LS1 5.7 Liter Passenger Car
Material: Aluminimum
Part Number:
12559806 (1997-98) Chambers = 69cc
12559853 (1999-00)
12564241 (2000-03)
Combustion Chamber Volume: 66.67cc
Compression Ratio: 10.1:1
Intake Port Volume: 200cc
Exhaust Port Volume: 70cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches


Casting Number 243
Head: 2001 LS6 5.7 Liter Passenger Car
Material: Aluminimum
Part Number:
12564243
Combustion Chamber Volume: 64.45cc
Compression Ratio: 10.5:1
Intake Port Volume: 210cc
Exhaust Port Volume: 75cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches

Casting Number 706 and 862
Head: 1999+ LM4 4.8L / LM7 5.3 Liter Truck
Material: Aluminimum
Part Number:
12559862
12561706
Combustion Chamber Volume: 61.15cc
Compression Ratio: 9.5:1
Intake Port Volume: 200cc
Exhaust Port Volume: 70cc
Intake Valve Diameter: 1.89 inches
Exhaust Valve Diameter: 1.55 inches

Casting Number 873
Head: 1999-2000 LQ4 6.0 Liter Truck
Material: Cast Iron
Part Number:
12561873
Combustion Chamber Volume: 71.06cc
Compression Ratio: 9.5:1
Intake Port Volume: 210cc
Exhaust Port Volume: 75cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches

Casting Number 317, 035
Head: 2001+ LQ4 and LQ9 6.0 Liter Truck
Material: Aluminimum
Part Number:
12562317 -LQ4
12572317 -LQ9
12572035 -LQ9
Combustion Chamber Volume: 71.06cc
Compression Ratio: 10:1 LQ9 Flat top pistons
Compression Ratio: 9.6:1 LQ4 Dish piston
Intake Port Volume: 210cc
Exhaust Port Volume: 75cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches



It takes about .005" milling of the block deck to remove 1cc of volume. It takes .007" milling to remove 1cc from an LS1 head
Simple Milling Math:

You have a stock 66cc chamber and you want to get down to 63cc

66-63 = 3. You have to remove 3cc's

.007 x 3 = .021. So to get your 66cc chambers down to 63cc you'd have to mill ~.021.

You can also do the reverse, say you want to mill a head .030 to figure out how many CC's that removes you take .030 / .007 = ~ 4.28. Milling a stock 5.7 head .030 puts your chamber at ~ 62.



241 cast heads were Die Cast which is a process that smooths up the ports a bit compared to the Sand Cast procedure that was done on the 806 and 853 heads. Once ported any "advantage" the 241 cast had is moot.

Same Info goes for the 4.8L/5.3Ltruck 862 and 706 Head castings
While the 706 Heads are a SPM = Semi Permanent-mold And considerd to be a more consistant head casting then the 862 wich are Sand cast, Once ported There Is no difference.

--------------------------------------------------------------------------------
799 Vs. 243 Info Coppied From pillboxesghost Post's in ths thread https://ls1tech.com/forums/conversio...l#post10241473

This appears to be one of the common misconceptions about heads having the 243 casting no. -- they are not necessarily LS6 head assemblies. The LS2 heads (243 or 799 casting) have the "heavy" standard LS1 valves. However, they do have the LS6 springs.

Only the true LS6 engine heads have stainless steel (not titanium) hollow stem valves (the exhaust stems are sodium filled). These valves are slightly longer that LS1 valves too.

The LS7 heads do have titanium valves.

New LS2 heads are about half the price of new LS6 heads (check sdparts.com). GM is "really proud" of those hollow stem valves!

Oh, if you have the 799 castings -- the only thing "Corvette" about them is the valve springs/retainers! Still a desirable set of LS1 heads though!

Supposedly, the 243 mold was done at GM Research, the 799 mold furnished to other vendors. The same vendor may have the 243 and 799 mold.

Both heads have identical sized intake and exhaust valves.

skyhighsami

iTrader: (8)

I ordered some pistons today. They are from an LS2, so I am getting the flat top pistons, and the upgraded rods. I am really excited. I am maybe even thinking about getting the 243 heads and have them worked a little, or I will keep the 317 castings. I just want to make the truck have good usable power and torque, since it is in a heavy truck that I use to tow with. So now I just need a cam, get my Trailblazer SS intake, and some long tube headers to replace the Gibson shorties. Thanks for the info guys

1FastBrick

iTrader: (17)

I would Just stick with the 317 Since you already be at 10:1 going any higher on a street driven car or truck especially since you plan on Towing with it, seems like you would just be asking for a problem. Haveing the 317 worked over wouldn't hurt either... Head for head In stock form, other then the combustion chamber being smaller on the 243's I don't see a diffrence to justify the expense of buying another set of heads... I would Use the money towards Getting your existing heads upgraded or trading them in towards some ported heads.
At bare minumum I have seen the 243's go for as low as $200 I wana say $300-$500 is avarage on what i see them go for Used.
Your gonna wanna go through them at the very least. Which would probally cost around another $200 If you spend money on any other parts to up grade them. with out even porting them your starting to get close to the Getting a done set Of reworked heads from one of our sponsers.


Just My .02 worth.... Im done

skyhighsami

iTrader: (8)

Would upgrading to the L92 setup not be worth it? I am planning on having a complete motor ready to go to drop in the truck when it comes time. Would there be any benefit to maybe running the CR in the 10.5 range? I was thinking about maybe having the 317s decked and worked. I have already spoke with my machine shop and he said that he could do it for around 450. If I stay with the 317s I am going to run a Trailblazer SS intake, if I go L92 then I will be swaping to that intake. I just want a strong 400-450 rwhp truck that makes good power through the midrange and bottom end. I don't want to run a monster stall in the 80E either, I would like to keep it small because I do plan to tow.