What is the thread size on the temperature and pressure senders?
The temperature and pressure senders have a 1/8" npt connection (male).
LS1 Metric Connections
For LS1 applications you will most likely need a metric to 1/8" npt adapter. For example: a M12 1.5 male x 1/8" npt female adapter for the temp sender and a M16 1.5 male x 1/8" npt female for the oil pressure sender. These are not included but can be readily found on eBay and Amazon.