I rigged up a separate temp gauge and it was hot. checked resistance on the regular sender and it matched the gauge through the full range, so it's not the gauge
I also checked the WP shaft for slippage and it's not slipping. I seriously have don everything you can do. At this point I need to let it go, it gets up close to that 3rd line on a consistent basis but not over. Now that my grounds are clean (and my fuel gauge reads full!!!) the gauge doesn't jump any more. I'm not loosing coolant, my fans are coming on, it's within "safe operating range" so I just need to live with it and keep a close eye. It's all i can do. Thanks for all your input on this guys.