It seems that driving between about 30-35 mph my trans is indecisive about what gear to be in. I see the rpms rise a few hundred then stumble back down. Trans fluid and filter were replaced a couple months back.Any ideas?

 

Normal. 2 things occur ...

1) as you stated, trans can't determine a good gear - wants to "hunt" between 3 & 4.
2) the torque converter lockup will also lock/unlock at speeds this low - it can lock in 3 or 4, and at speeds as low as 30mph

One way to get past this - switch to D instead of OD in these rare instances. Different grades will react differently, etc. So, just switch to D for awhile, then can switch back to OD when grade increases/decreases, or road changes, or speed limit changes.

If you are driving the car "properly" - the only place this should occur is in a 25mph zone. Since you should be driving 10mph over the speed limit (it's a Camaro!!!), it should only happen in a 25mph zone - get into a 35+ zone where the Camaro will be happy!