Does anyone make a carburetor intake for the 8.1/8100
big block chevy.I have 2 of these and would like to run them with a single 4 barrel.they have large LS1 type ports,long rods and some other good features.I'd like to use them with out fab-ing my own and running EFI  

Ugh! You might try Edelbrock or Holley. The aftermarket really hasn't done anything with the 8.1 motors yet because they're not really "out there" to warrant parts like that. While the 8.1 is a good motor, it's only seen use in the 3/4 and 1 ton trucks, industrial stuff, an limited marine applications.

If no one has a production manifold, I'd check with Wilson Manifolds, they might have a basic pattern for making a fabricated intake for that motor, or can build you one that won't break the bank.