862 Head Question
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862 Head Question 2007 Avalanche 5.3
I have a set of 862 heads to install. I'm mostly looking for torque. It already has the AFM deleted and a Truck Norris cam (216/220). Would I want to port these heads before installing or leave them stock?
I have a set of 862 heads to install. I'm mostly looking for torque. It already has the AFM deleted and a Truck Norris cam (216/220). Would I want to port these heads before installing or leave them stock?
I'm curious about this as well. My 2001 Camaro SS has a 5.7L LS1 and 862 heads. I believe the cam to be aftermarket as well but I don't know anything about it. I've never had it on a dyno.
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From: Central Cal.
That and any milling needed to bring the compression to where you want besides a .040 head gasket to bring the quench up to where it should be.
I mean if you want the most gain do port them, but stick with the stock intake valve size on a stock 5.3 bore. In a truck if you are doing truck things (towing etc) you might need to run premium fuel etc as you raise compression far beyond stock. I've actually found some small bore VR or Mahle composite gaskets in the 0.040" range also.
Last edited by slowride; Oct 6, 2023 at 10:15 AM.
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Thanks. I think I have all the parts, now I'm waiting for a 4-day weekend to do it. My lower back can only take a few hours a day. The truck is a spare and I can leave apart for a week or two but I don't want it down that long.
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@GAtsma
Put all this back together and when I add antifreeze, it's pouring right out of the back of the engine. I'm assuming it's a head gasket issue. I double check everything. I was **** on all the torque specs. APR bolts.
I'm at a loss but giving up for today.
And I mean as I add it
Put all this back together and when I add antifreeze, it's pouring right out of the back of the engine. I'm assuming it's a head gasket issue. I double check everything. I was **** on all the torque specs. APR bolts.
I'm at a loss but giving up for today.
And I mean as I add it
Last edited by bighdx; Feb 4, 2024 at 03:47 PM.
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Got to be head gasket related. Cosmetic only showed 1 part # for these. Was I supposed to look for a right and left?
Or can this be intake gasket related? I didn't get oem intake gaskets that had the lock tabs.
Last edited by bighdx; Feb 4, 2024 at 05:26 PM.
