If your looking to run a LS7 for racing or older carb based vettes GM now has a intake for that

25534394

LS7 4-Barrel Intake Manifold
GM Racing design for use on LS7 heads
As-cast design requires no porting for maximum performance
Includes mounting bolts and instructions
Uses LS7 carb intake gasket set P/N 19172113
Machined for 4150-style carburetors and has 3/8' NPT vacuum boss
Also available with injector bosses P/N 25534413

Note: LSX Ignition Controller P/N 19171130 is required for carbureted applications

Here is one for LS3/L92

25534401

L76/L92 4-Barrel Intake Manifold
GM Racing design for use on 'as-cast' rectangle port Gen IV cylinder heads
As-cast design requires no porting for maximum performance
Includes mounting bolts and instructions
Uses L92/LS3 carb intake gasket set P/N 19172114
Machined for 4150-style carburetors and has 3/8' NPT vacuum boss
Also available with injector bosses P/N 25534416

Note: LSX Ignition Controller P/N 19171130 is required for carbureted applications.

This one is for LS1/6/2 engines

88958675

LS2 4-Barrel Intake Manifold
' Allows you to install a four-barrel carburetor on a LS series engine with cathedral ports (LS1, LS6, LS2)
' Cast aluminum open-plenum intake manifold accepts a 4150-style square-bore carburetor
' Uses LS2 carb intake gasket set P/N 19156564
' Bosses for EFI injectors for custom applications
' Bolts and instructions supplied

Note: LSX Ignition Controller P/N 19171130 is required for carbureted applications.