Running Rough

HERE'S ONE THATS GOT ME TALKING TO MY DOG...
I'VE GOT A 350 CU INCH CHEVY IN MY CAR GOOD COMPRESSION
ROLLER ROCKERS,2.02 CAMEL BUMP HEADS ETC.ETC
AFTER I CHANGED THE HEAD GASKETS,TIMED IT ,SET THE CARBS
EVERYTHING LOOKED O.K. DURING RUN UP HOWEVER
THE LEFT SIDE OF THE EXHAUST IS RUNNING NOTICIBLY COLDER
THAN THE RIGHT SIDE EXHAUST.
SINCE I HAVE THE OLD STYLE DISTRIBUTER WITH PERTRONICS
I CHECKED THAT OUT FIRST, THEN NEW PLUG WIRES AND PLUGS
RE CHECKED THE TIMING STILL RUNNING ROUGH
ANY IDEAS OUT THERE

I'll opt in with a wild-a** guess....
Check the plugs. I'm thinkin' that the intake is sealing on one head, but not the other. The bank that isn't sealing would therefore be drawing in a leaner mixture and running hotter and possibly mis-firing. Here's a routine I use on every motor I build since I figured out how to do it.....
http://streetmachinesoftablerock.com...opic.php?t=350

thanx for the input guys, i went back to square 1 and removed the rockers, just to get a look at the springs push rods etc
#7 exaust lifter feels like it has collapsed....ordered a new matched set of comp cams lifters and pushrods...
should have baby up & running this time tomorrow
will post anything else i find ....
i know some people reuse gaskets, i always thought they were like condoms...only use once...