How much can you safely mill the aluminum lt1 head? I think I have heard as much as .030. What is the net cc per thousandth milled? When do you have intake manifold sealing/matchup problems? What head gasket should I use to get more compression with reliability? Should shim gaskets make me nervous with an aluminum head mating a cast iron block? Thanks,
Chris
Dayton, OH

 

Good luck!!! I've asked this question a few times, no answer

 

1cc for every .006 milled (flat milling).

What's your target for static compression? May not be necessary to mill too much if we know this.

Yes, the intake will need a correction for heavy milling (.030 would qualify). Same goes for angle milling... the intake needs correction.

WRT head gaskets, the composites from Fel-pro and Rol are good gaskets. If the heads and block are machined with the right surface finishes, you could use a Multi Layer Steel (MLS) gasket. You need to determine a quench distance before considering a gasket. All plays a part in determing that target static compression ratio.

-Mindgame

 

will a machine shop know what to do to the intake if .030 is taken off of the head? I'm planing on taking off .020 on my aluminum heads ...will any intake work be needed, if so which surface and how much ? Thanks,

 

The shop here says that the head can be safely milled .030. If the block is decked, that needs to be done too, then, they place the heads on the block and measure where the ports line up on the intake. They can then determine how much needs to be milled off of the intake. It's no big deal I guess.

 

i had mine milled to 50cc i dont rember how much they took off though

 

The major limiting factor is the intake valve seat location. With stock seats you can take off .010 - .015 without issue. More than that and you need to pay close attention as to how close you are to the seats... I've seen some "out to lunch" seat locations (as far as distance from the deck) from GM on these heads.
Steve...