Hello! Did you replace the thermostat as well? It's typically done along with a new water pump and rad. I believe the Behr 87 degree celsius is the most recommended one. And as far as the water pump goes, oem is basically the only recommended pump for the car, so you might just want to scrap the airtex and get a m-b.

-Chris

__________________
Streetside: 1987 Mercedes 300E Petrol Blue/Green
2014 Ford Mustang Grabber Blue
1999 Ford Ranger Green

Dockside: 1968 Eltro 17
1985 Silverton 34C