[fuzzypuppy]

I've been regestered on this board for some time, and have done my best to help others with problems i'm familiar with, and generaly put my 2 cents worth in where GMC'S are concerned. I'm no genious but am considered pretty good mechanicly, but i'm having a few problems that have so far stumped me.
One is the battery light in the dash flickers, the gage shows everything is fine, ie its charging, I took my baby to autozone and had them run a test and the test showed everything is fine, alt charging. but did show a weak battery, i replaced the batt thinking hah! but guess what, the light still flickers. I do have a duel batt setup with the proper isolator etc all in place, the second batt a deep cycle marine/rv was checked and found fine, which is good since it is as well brand new.
im stumped on this because i have no problems with mysterious dead batt situations. Does anyone have any ideas where I could proceed from here to solve the problem?
Also I'm having problems with a slightly erratic idle. its fine when cold the problem only starts when the truck is warm, and once in awhile sitting at a light it will surge, just slightly but its noticable, I service this truck faithfully and have already checked the obvious items, vacume lines etc, at first i attributed the idle to a new cam I installed about 6 mos ago but have since dismissed this theory, it was the largest cam that would work with the computer controls, basicly an R/V style. but not large enough to cause the irratic idle since its not a lope like a rough cam idle would bring. first thing i changed in attempts to solve this was the o2 sensor. as well when i changed the cam i throughly cleaned the egr, so after all this im at a loss, anyone have any ideas where to go from here?
For some background the truck is a 91. 2500 w/a 5.7 170.000 mi. on it.
it does need valve seals,'smoke only when it is first started in the morning' and I have a beautifull set of vortec heads waiting for the $ to get the intake and other goodies to make this swap, but doubt the worn seals would cause the idle troubles.
anyways any help would be greatly appreciated.