When spraying an LT1, and then inspecting the plugs, what causes the the front two cylinders to look rich, the middle 4 look fine but the back two look lean? Not my car but a friend had that problem with his 97.

 

wet im assuming? probably the noxzzel is too far from the t/b...since fuel is heavier it falls more wuickly than air, so it falls into the first cylinders and the abck ones only get n20..which is very bad...
id say try moving the nozzel a little closer to the t/b

 

What size shot is he spraying?

 

As you can see, without knowing what kind of system it is, and where you have the hardware located, its almost impossible to know the answer.

 

It was a 200 shot via a NX Dual Nozzle, the nozzles were located on the intake elbow right in front of the throttle body

 

It wouldn't hurt to make sure the nozzles are aimed properly. In my own personal experience with the NX dual nozzle kit, I noticed the nozzles liked to move around a bit in the fitting which caused them to point away from center and more towards the top of the intake elbow/throttle body.

 

The LT1 intake design is the problem. It is common for number 8 and sometimes number 6 to run lean.
Dave

 

The car in question has since been sold, guess a direct port set up would cure the problem.

 

6 and 8 ??

not 5 & 7 ??