Best cometic head gaskets?
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Best cometic head gaskets? What would be the best cometic head gasket to use for my boosted 5.3? I am using 317 heads on a 5.3 non-decked block: should I invest in the machine work for shaved heads and a decked block?
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From: PA/MD
I'd go with a 5.3L MLS gasket with .051" thickness to give proper quench area if your running stock pistons with an undecked block.
Since your boosted I wouldn't mill the heads (unless they need trued up), but if you get the heads ported you PSI will drop, and at the same time make more power because of the increased flow
Since your boosted I wouldn't mill the heads (unless they need trued up), but if you get the heads ported you PSI will drop, and at the same time make more power because of the increased flow
I'd go with a 5.3L MLS gasket with .051" thickness to give proper quench area if your running stock pistons with an undecked block.
Since your boosted I wouldn't mill the heads (unless they need trued up), but if you get the heads ported you PSI will drop, and at the same time make more power because of the increased flow
Since your boosted I wouldn't mill the heads (unless they need trued up), but if you get the heads ported you PSI will drop, and at the same time make more power because of the increased flow
Also is engine going to be street driven? If so I would shoot for 9.5:1 compression so getting the heads shaved a little bit is probly not going to matter much.
Thread Starter
On The Tree
iTrader: (13)
Joined: Sep 2009
Posts: 118
Likes: 0
From: Virginia beach VA
I'd go with a 5.3L MLS gasket with .051" thickness to give proper quench area if your running stock pistons with an undecked block.
Since your boosted I wouldn't mill the heads (unless they need trued up), but if you get the heads ported you PSI will drop, and at the same time make more power because of the increased flow
Since your boosted I wouldn't mill the heads (unless they need trued up), but if you get the heads ported you PSI will drop, and at the same time make more power because of the increased flow
A 5.3l gasket wont clear the 72cc combustion chamber in the 317 heads. You need to use a 6.0L gasket (.051 thick as well) or a cometic 4.030 bore. These are what I'm running on my ls1 with 317's http://www.texas-speed.com/shop/item...d=603&catid=36
Also is engine going to be street driven? If so I would shoot for 9.5:1 compression so getting the heads shaved a little bit is probly not going to matter much.
Also is engine going to be street driven? If so I would shoot for 9.5:1 compression so getting the heads shaved a little bit is probly not going to matter much.
The heads have roughly 80K on them. I am going to have them checked once I receive them. the engine will be street driven as well, using all stock internals and the heads will be left stock as well. I dont plan on decking the block either.
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From: PA/MD
A 5.3l gasket wont clear the 72cc combustion chamber in the 317 heads. You need to use a 6.0L gasket (.051 thick as well) or a cometic 4.030 bore. These are what I'm running on my ls1 with 317's http://www.texas-speed.com/shop/item...d=603&catid=36
Also is engine going to be street driven? If so I would shoot for 9.5:1 compression so getting the heads shaved a little bit is probly not going to matter much.
Also is engine going to be street driven? If so I would shoot for 9.5:1 compression so getting the heads shaved a little bit is probly not going to matter much.
thanks for clearing up my mistake, didn't realize the clearance was that close on the valves
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Also I would upgrade to dual valve springs, FI needs a stable valve train.
These are the 2 options for the 317 heads.
GM MLS http://www.texas-speed.com/shop/item...d=880&catid=36
Cometic MLS http://www.texas-speed.com/shop/item...d=603&catid=36
GM MLS http://www.texas-speed.com/shop/item...d=880&catid=36
Cometic MLS http://www.texas-speed.com/shop/item...d=603&catid=36
These are the 2 options for the 317 heads.
GM MLS http://www.texas-speed.com/shop/item...d=880&catid=36
Cometic MLS http://www.texas-speed.com/shop/item...d=603&catid=36
GM MLS http://www.texas-speed.com/shop/item...d=880&catid=36
Cometic MLS http://www.texas-speed.com/shop/item...d=603&catid=36
I did a search and stumbled on this thread. I'm just curious....I am running this combo as well. Why do you need a 4.030 bore in the cometic version thats intended for a 6.0? If the engine is not bored, shouldn't you be ok with a standard bore and not a .030 over bore?
I did a search and stumbled on this thread. I'm just curious....I am running this combo as well. Why do you need a 4.030 bore in the cometic version thats intended for a 6.0? If the engine is not bored, shouldn't you be ok with a standard bore and not a .030 over bore?
Copper spray because some guys feel cometics need this to help seal better. IIRC Cometic requires an RA of 50 on the sealing surfaces....
What he said ^^^
I did not use copper spray on my cometics, just wiped the gaskets, heads and block deck with brake cleaner and bolted them on.
