Two of the injectors are circa 1984 with the engine rebuild. Three were replaced maybe about 100,000 miles previous by the dealer.
Normally all are replaced yes, but they tested them all and saw that I was fiscally challenged at the time.
I've run redline almost religiously and the car gets regular highway use. There is no nailing whatsoever.
It may be tight valves. I will do a valve adjustment, but maybe the adjusters aren't holding their positions for long.
It could have something to do with the fact that this other mechanic I used to use, put the cam gear on backwards with the chain one tooth off TDC. I ran the car that way for a while making myself nuts trying to figure out what that wierd noise was (possible ever so slight valve piston contact noise)
Finally got it figured out thanks to this site and corrected it and the car seemed to run fine after that.
Only recently has the fuel comsuption gone up with increased smokiness at idle. There is also a possible fuel leak, I smell it occasionally.
I will now duck under my computer and await the incredulous reactions for with holding this info so far.:p