862 heads...
09-21-2010, 07:10 PM
#17
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Here is the thread link.
https://www.performancetrucks.net/fo...d.php?t=434396
Snippit from that Thread:
"Casting Number 706 and 862
Head: 1999+ 4.8L / 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
Stock Head Flow Numbers
Chamber 61.15 cc----0.100--0.200--0.300-- 0.400--0.500---0.550---0.600
Intake 200 cc----------63 ---128----179-----210----218----221-----226
Exhaust 70 cc----------54 -- 93 ----121----145-----163----168----174
What you need to know:
These small combustion chamber truck heads offer no advantage over an LS1 head except the smaller combustion chamber. This along with milling of the deck surface will allow a slightly higher compression ratio to be achieved. Because of the smaller intake valve installed in these heads a valve upgrade is practically mandatory."
https://www.performancetrucks.net/fo...d.php?t=434396
Snippit from that Thread:
"Casting Number 706 and 862
Head: 1999+ 4.8L / 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
Stock Head Flow Numbers
Chamber 61.15 cc----0.100--0.200--0.300-- 0.400--0.500---0.550---0.600
Intake 200 cc----------63 ---128----179-----210----218----221-----226
Exhaust 70 cc----------54 -- 93 ----121----145-----163----168----174
What you need to know:
These small combustion chamber truck heads offer no advantage over an LS1 head except the smaller combustion chamber. This along with milling of the deck surface will allow a slightly higher compression ratio to be achieved. Because of the smaller intake valve installed in these heads a valve upgrade is practically mandatory."
10-21-2010, 11:59 AM
#20
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862 heads to play with
Originally Posted by i have 2000 4.8 rc silverado came with 862 heads I have them port polish and mill .025 flat pistons . they came with 61.15 cc chambers 200cc intake ports and 70cc exaust. work on it, they are great heads,: great potencial,have at least 2 angle valve job you will see.ls engines love compression they are two bolts main bearings with a nice tune NOT a hand held tune put that engine to rev and hold on dude! Nice 3.73 or 4.10 will be like Dr. Jeckill and Mr. Hide
:secret2::secret2::secret2::secret2: 06murder;4537006
:secret2::secret2::secret2::secret2: 06murder;4537006
can someone tell me something bout the 862 heads...plz
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