muffler gets white hot and the motor makes apopping noice on 1998 Chevrolet Blazer

i just put a new motor in my 98 blazer and now it is making a popping noice and the muffler and cadalice converter get white hot i changed the wires plugs and cap

Asked by for the 1998 Chevrolet Blazer
4 answers 1 comment
Was the new motor a 'long block' , 'short block' or complete used motor from a salvage yard? Popping through intake? Valve or timing(or both) issue.
check to see if your converter is plugged
did and its not
poss running very lean
Recheck ignition timing and plug wire placement to be sure #1 is where it is supposed to be! Running rough, lack of power?