hey i found a real nice iroc at then junk yard it was missin the intake manifold and the carb so i took it off this parts car i had but anyway i started it up last week and set the timing by ear, i noticed the car idled rough so i guessed the timing was off so i messed around wit the distrubutor a little and found out that no matter where i set the timing it would still idle rough so i'm thinkin the car has a cam or something cause the engine had some work done to it...(headers,intake,carb,3" cat back)but by the time i found it all that was left was the headers and 3" cat back...lol anyway is there anyway to find out if it has a cam with out opening it?
and wat else could cause the car to idle rough
its a 305 LG4 i think at least that what the vin says
P.S the top half of the engine is off my other camaro which was running fine
thx in advance:hail:

 

anyone????