1995 Camaro 3.4L V6 stock

Hey guys, new to the forums ::Waves::

I've been having a problem with my car that I really haven't looked into for over a year. I can't even pinpoint when it actually happened, but for some time now when I'm accelerating I cannot get past 3500rpm without the engine spuddering and not accelerating any further. I can't tell if the engine is just getting flooded or if maybe the sparkplugs aren't firing at that high rpms. Sitting idle I can rev the engine just fine as high as I want, but not when accelerating.

I did change out my sparkplugs at one point and it CURED the problem for about 4 days. After the 4th, we were back at the problem.

Have you guys ever heard of this and/or have any suggestions?

Thanks!