athakur999 - the oil temp and press probe is 1/8 PT. That actually works better for WRX's since most of the oil sandwich filters and the Subaru oil galley plug is 1/8 PT.
boostinwrx - you can purchase the 45mm mech boost gauge from our site. The installation guide to make the swap while using your stock housing is here:
click me
Thanks,
Thaison