I ran a tank of of Chevron mixed with a can of Seafoam thru my carbs and then two more tanks with a 1/2 can then let it set for a week soaking while I ran out to Ft Worth. Today it was running better but still idling rough. I tried to get a vacuum reading and the hand was fluctuating on all the cylinders so bad I couldn't get a good reading. Also my right rear exhaust pipe at the block was reading a temp of around 600 deg and the rest were 250-300. Most of my tools and my manual are in Tennessee and I'm basking here in Florida acting like a Snowbird. I can't remember what causes a vacuum to act like that. Any suggestions? Also, can the 600 degrees on the right rear cylinder do any damage? Would appreciate any thoughts. Thanks.