Engine tech pistons sit down in the hole, they are not out of the hole (with an unmilled deck). I literally just did this exact same build. LS2 rods with engine tech flat top pistons, bored .030". Only difference is my cam is the TSP224R .600"/.600" with 112lsa and 110 centerline and my 799 heads were milled .008".

Engine tech piston compression heights are typically .010"-.015" below factory to make up for the deck being milled and not running into any issues sticking out of the hole too far. With an unmilled deck on my block, my pistons sat down in the hole .004"-.005", depending on cylinder. With .008" milled 799's, stock otherwise, and that cam, I had roughly .160" on PTV clearance on the intake valve and far more on the exhaust valve (exhaust valve didn't even leave an indentation in the putty I placed in the cylinder on top of the piston). With stock gaskets, I believe I am roughly 11.1:1 compression. I am spinning 6200rpm just fine and it runs great.

 

If I'm not mistaken, safe PTV clearance is .080" intake and .100" exhaust.

 

Without knowing if your deck was milled or not, it's hard to give you an accurate compression ratio. But with what you've said, I'd say you're well above 11:1 and shouldn't have any issues with PTV clearance. But you need to check it yourself to verify.

Here is mine right before the heads went on.

 

You also need to know exactly which head gaskets you are running. I ran the oem 6.0/6.2 gaskets. .051" compressed with a 4.080" bore. There are several different bore sizes available, that will affect compression as well.

 

Thanks for the info Ray Finkle! i will check out the PTV later on today. as far as head gaskets the machine shop gave me HC364-A also from engine tech.from what i googled they are .51 thickness but not too sure on the bore?

 

That gasket cross referenced over to a fel pro number showing a 4.040" bore. That's a little close for comfort to the cylinder bore in my opinion. Measure the gasket bore yourself to verify.

 

what is a good gasket that i can use if this gasket is a 4.040?

 

What compression ratio are you after? If you're worried about it being to high as is, you can run ls9 gaskets to drop it a little, but if you want it higher, then I'd just run the standard 4.080" bore 6.0/6.2 gaskets. I got mine from summit. Luckily that gasket is the cheapest oem gasket there is, I paid roughly $30 each for them. Ls9 gaskets are around $50 each.

 

LS9 gaskets

https://m.summitracing.com/parts/nal...acUxoCKuXw_wcB

Standard 6.0/6.2 gaskets

https://m.summitracing.com/parts/nal-12610046