ive got a battery charging problem...i think. heres the senario:

new 140 amp alt
optima red top tested just fine

but my problem consists of a few things actually.

when i start the car the batt gauge is sometimes showing halfway between the middle (straight up and down) and the very high extreme (all the way right) and then it sometimes drops to straight up an down. but it does this at sparatic times and no set pattern. no matter what, after i run the car the battery is never fully charged, even if i just charged it started the car and the parked it a few minutes later.
the battery gauge and tach also tick back and forth when the turn signal is on. now i know these gauges really arent up to the task of giving good results but there is a problem somewhere.
now the weird problem, sometimes my starter just clicks when i turn the key over. it will click and click and not sure when but always eventully start, unless the battery is freshly charged then it always starts right up and much quicker than ever before.

now i had a bad 105 amp alt and replaced it with that 140. when i did that i removed my smog pump and added a underdrive crank pulley. the stock belt seemed to fit fine with this swap. but it didnt change the output so i went back to stock pulleys and had to buy a new bigger belt to go along with it.

any ideas on what my problem is? my batt tested good and the alt is a new 140 amp. i thought the underdirve pulleys might cause some problems (even though they worked fine at first) so i changed back to the stockers with no positive result. im stumped...