What kinda stat are you using? What temperature? Just because its new doesnt mean it works. I bought the Napa Premium as well as the MOROSO / Mr. Gasket type. Both 160º. I bench tested them both and the NAPA opened at 157º and full port at 165º. The MOROSO/Mr. G style began to open at 172º and was full port by 185º...You can't trust any of them really.

I paid $12 for one 10 years ago and my engine was hitting 170º all day along in traffic and the freeway. 22" 4-core Radiator + Shroud, High Volume Water pump (cast iron), 7 blade fan + Hayden clutch. All timed and dialed in. 10:1.

I can't seem to find a decent stat anymore. She runs close to 185º all day now (given I am in a different region of the world but the weather is the same)

A trick I used to do on my Slant 6 Dart was open three 1/8" holes in a triangular formation on the surrounding area of the stat, chamfer the holes on both sides. My dart was riding 180º all day with a 180º Stant Stat