I put a diffrent motor in a 96 z28 ran it for a couple hundred mile and it ran great then it started to miss real bad and the exhaust manifold started to glow i found that because of the metal heat sheild on the back plug wires on both sides had mad the wires come off the plugs and i put them back on and the same problem so i put new plugs and wires on the car and all the old plugs were real black and fouled so i don't think the car running lean is the prob but i am fresh out of ideas it still misses at all speeds and the dr side manifold glows

 

Glowing manifolds is usually from restricted convertors. The black soot on the plugs indicates for what ever reason, it was running too rich. One of the most common causes of restricted cats. Running rich usually screws up O2's also.

 

The only times I've ever noticed my manifolds glowing have always been after limping home from a catalytic converter failure. I really hope that wouldn't have resulted in any other issues because the last time it happened my car went into long term storage shortly thereafter.

 

agree put your hand over the exhaust tips rev it and I think you'll feel the problem, don't run this car to long like this.

 

what he said