5.3 with flat top pistons & 706 heads with valve job
Feb 12, 2012 | 04:34 PM
#1
Thread Starter
Staging Lane
Joined: Jun 2005
Posts: 83
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5.3 with flat top pistons & 706 heads with valve job
Building a 5.3 and thinking about flat top pistons with the stock 706/862 heads. If i get some 2.0 intake valves from say a 317 and have a performance valve job done is this a good plan and what will the CR be?
Feb 12, 2012 | 05:11 PM
#2
Did I hear you say 5.3 with flat top pistons? 
Compression ratio will be 10.5 , but the bore on this block is oversized so it will not be the same a stock 3.780
Compression ratio will be 10.5 , but the bore on this block is oversized so it will not be the same a stock 3.780
Last edited by TXSZ66AVLANCHE; Feb 12, 2012 at 05:25 PM.
Feb 12, 2012 | 06:17 PM
#3
Approx 10.5 deppending on gaskets and if the deck needs to be cleaned up on the head or block. The 2.0 valves may shroud a little in the stock bore.
You can get 1.95 valve. Or have them turned down. If your really looking to get Max flow use an after market valve thats back cut.
Honestly your best bet is to get a done set of heads through a vendor. You can easily spend $500 on parts and labor with out even getting any port work done.
You can get a nice set of CNC Ported heads Through SDPC. they start at $899 depending on spring option.
If you feel that is to much compresion Use an LS1 Head. they have a larger cumbustion chamber. They will net you around 9:9 -1
You can get 1.95 valve. Or have them turned down. If your really looking to get Max flow use an after market valve thats back cut.
Honestly your best bet is to get a done set of heads through a vendor. You can easily spend $500 on parts and labor with out even getting any port work done.
You can get a nice set of CNC Ported heads Through SDPC. they start at $899 depending on spring option.
If you feel that is to much compresion Use an LS1 Head. they have a larger cumbustion chamber. They will net you around 9:9 -1
Feb 12, 2012 | 11:33 PM
#7
Where are those flat top pistons offered? I have only seen the Wiesco pistons with -2 and -7cc offered for the 5.3 (I believe the -2cc gives 10.4:1 compression with stock heads though).
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Feb 12, 2012 | 11:40 PM
#8
Feb 12, 2012 | 11:41 PM
#9
Approx 10.5 deppending on gaskets and if the deck needs to be cleaned up on the head or block. The 2.0 valves may shroud a little in the stock bore.
You can get 1.95 valve. Or have them turned down. If your really looking to get Max flow use an after market valve thats back cut.
Honestly your best bet is to get a done set of heads through a vendor. You can easily spend $500 on parts and labor with out even getting any port work done.
You can get a nice set of CNC Ported heads Through SDPC. they start at $899 depending on spring option.
If you feel that is to much compresion Use an LS1 Head. they have a larger cumbustion chamber. They will net you around 9:9 -1
You can get 1.95 valve. Or have them turned down. If your really looking to get Max flow use an after market valve thats back cut.
Honestly your best bet is to get a done set of heads through a vendor. You can easily spend $500 on parts and labor with out even getting any port work done.
You can get a nice set of CNC Ported heads Through SDPC. they start at $899 depending on spring option.
If you feel that is to much compresion Use an LS1 Head. they have a larger cumbustion chamber. They will net you around 9:9 -1
May be an answer I should know but, what do you mean by shrouding?
Feb 13, 2012 | 04:41 AM
#10