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demonheavymetal
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Got lucky at a local junkyard and snagged a set of 862 heads off a wrecked z71 2000-2006 body style. thinking about building these (port n polish, roller rockers, valves n springs to go with a nice cam) to put on my 06 gmc 4.8L . Am I correct in assuming these fit my motor? I thought they were basically the same as the 706's that are original on my motor. I got em for $150, a steal either way.
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kha4079
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could have pmmed me i have a complete set of 862s for 100 bucks plus shipping
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sprayedenali
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706s are better than 862s. i also have a set that i told someone id sell for $100... sorry
01 Silverado
kha4079
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i dont know who told u that lie 706 heads are better when thay arent. are EXACTLY IDENTICAL to the 862s only difference is The 862 casting came with and without the recess on the edge of the deck surface and a small triangle under the exhaust port lol Originally Posted by sprayedenali706s are better than 862s. i also have a set that i told someone id sell for $100... sorry
Last edited by kha4079; 06-26-2011 at 10:02 PM.
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sprayedenali
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same port design and combustion chamber, but they were cast by different companies and the 706s are alot cleaner of a casting... not near as rough as the 862s and therefore would have a smoother flow. minute difference, but they are different Originally Posted by kha4079i dont know who told u that lie 706 heads are better when thay arent. are EXACTLY IDENTICAL to the 862s
01 Silverado
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kha4079
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nothing some 80-120 grit sandpaper can fix Originally Posted by sprayedenalisame port design and combustion chamber, but they were cast by different companies and the 706s are alot cleaner of a casting... not near as rough as the 862s and therefore would have a smoother flow. minute difference, but they are different
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midnight04
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They are not even close to IDENTICAL!!!!! 706 Cast heads were SPM cast (Mold) and 862's are Sand cast (Pressed) The SPM cast is 100X better than sand cast heads. That is why the 243's are SPM cast over the truck version 317's, and the L92's 823 Sand cast VS the LS3's 821 SPM cast.. starting to see a trend? GM SPM cast all of the HP builds and sand cast the truck builds! The SPM cast is the better option stock for stock. Ported they are the same! You will find the sand cast heads have tons of slag in them making it more time to port them.............. You are starting to look like a real prick in here, After you jacked my for sale thread I looked up your posts and you are starting $hit all over! Originally Posted by kha4079i dont know who told u that lie 706 heads are better when thay arent. are EXACTLY IDENTICAL to the 862s only difference is The 862 casting came with and without the recess on the edge of the deck surface and a small triangle under the exhaust port lol
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sprayedenali
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Originally Posted by sprayedenalisame port design and combustion chamber, but they were cast by different companies and the 706s are alot cleaner of a casting... not near as rough as the 862s and therefore would have a smoother flow. minute difference, but they are different
hmmm.... Originally Posted by midnight04They are not even close to IDENTICAL!!!!! 706 Cast heads were SPM cast (Mold) and 862's are Sand cast (Pressed) The SPM cast is 100X better than sand cast heads. That is why the 243's are SPM cast over the truck version 317's, and the L92's 823 Sand cast VS the LS3's 821 SPM cast.. starting to see a trend? GM SPM cast all of the HP builds and sand cast the truck builds! The SPM cast is the better option stock for stock. Ported they are the same! You will find the sand cast heads have tons of slag in them making it more time to port them.............. You are starting to look like a real prick in here, After you jacked my for sale thread I looked up your posts and you are starting $hit all over!
01 Silverado
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midnight04
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Yup, you are on point with your "same port and combustion chamber post" They have the same 200cc intake runner and EX runners even the CB chamber are the same. The reason I say not even close, is the fact the sand cast heads (862's) collect more crud in the CB chamber Intake runner & EX runner over time due to the extremely jagged surface and extra slag in the ports, The SPM cast heads (706) don't collect nearly half as much! So over time the 706's will flow 2 times as well! When polishing most SPM cast CB chambers all you have to do is clean and run your polishing tool over it a couple times taking about 30 min's to do the entire head, sand cast (862's) are a f--kin nightmare you have to break out your sanding cartages, grinding tools and work all the.. Well for lack of a better word aluminum sand specks and slag before you take the polishing tool to them taking about 30min each chamber..lol here is a couple of picks of the last set of 862's I ported you can still see the sand specks in the chamber's. and I worked the heck out of those heads! 2.08 intake and 1.6ex tons of porting and valve seat work! It took me a day to get the chambers looking like they do in the picks, I stoped around the plug holes because they were my heads and not a clients, or I would not have stopped till they were GLASS! Ill post a pick of some SPM cast LS3 chambers after this post and you can see the difference they took me about an hour to polish up.lol Originally Posted by sprayedenalihmmm....
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midnight04
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Here are the SPM cast LS3 head chambers
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Originally Posted by sprayedenali
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