I use 10w-30 Castrol GTX and I LOVE IT. My step dad uses 5w-30 in his '91 Beretta with 485,000 original miles.

 

I use Amsoil 10-30 and have no issues with 63,000 miles stuff is $ 7 a quart but I love the way when the oil comes out at 2500 miles its as clean as when it went in.

 

i think i know what noise your talking about, it sounds almost like a cam tapping on metal more of a "rubbing" impact instead of a straight metal on metal impact, if we're on the same page.

it's what i have learned to call a "chevy" noise lol :P, i dont think its anything major, like jeff said it might just be parts not being lubed fully, but when the car warms up all is fine soo its no biggie, besides i been revving the **** out of my carwith that noise for almost a year now and it still runs strong and nothing has fell out of it and no problems with the motor at all so far.