nightbasser73

I'm getting ready to build a LQ4 6.0 liter for my sons truck and will be using 862 heads. My research shows this will give me around 10.5 to one with stock gaskets and stock pistons. I plan on freshening the engine and will probably go ahead and put in new pistons as well. Who makes dished pistons with the same dish as the factory piston? I was looking at the speedpro but open to other options.

1FastBrick

iTrader: (17)

You will need to check the pistons when you receive them. Most after market manufacturers assume the block deck needs to be surfaced during reman process.

Recently did an LQ9 with speed pro .020 over and they were .009 below the deck.

You can look into Silv-O-Lite as well.

nightbasser73

Thanks for the info!!! this truck is gonna be a fun driver so i figure 862 heads, ss2 cam, tbss intake and a freshening should get us where we want to be. I already had the 862 heads so thats why i want to stay with a stock dished type piston.

dantheman1540

Any chance you and Shakenfake are building the same truck?

RedXray

Dose the factory piston skirts show a lot of wear? If not carefully clean the carbon from the ring land grooves and just run those. If you have access to 93 octane you have a good opportunity bumping the compression up another number with LQ9 flatops. The SS2 camshaft likes compression and specs with 10.5 plus as a minimum CR. If you do decide on new pistons that's a thought. What year LQ4 and dose it have the good rods with floating pins?

nightbasser73

Lol i'm not sure. I'm a newbie on here i'll have to look him up on here.

nightbasser73

The lq4 is an 04 so it might have floating pins but i think still the gen 3 rods. I don't think the flattops will work with 862 heads as that will throw us up over 11:1. Per my research the 862 should have us right at 10.5 to 1 from the sources i have found. I'm open to all information and suggestions that you guys may have and I sure appreciate the help!! For reference the lq4 and 4l80 are 04 out of 3500 van. 180k miles for $800 for both i couldn't pass it up

dantheman1540

Nice looking truck! Only asked because someone else just started posting questions about an LQ4 with 862s and I haven't seen a ton of people running that combo.

Curious why replace the pistons if the LQ4s will work with what you are doing? I'm running LQ4 pistons with 862s and I think you are correct it's right at 10.5-1 I'm actually going to run a calculator now. Also are you ever going to boost it?

RedXray

If they float they're the good rods (same as gen4). I'm at 11.4 static with no knock, running 27* degrees total timing advance, OEM flat tops in a LQ9 with 62cc chambers.

nightbasser73

Thats some pretty good compression. Got me to thinking now. What head are you running and which head gasket?