I'm waiting for my Flowkooler hi-flow water pump (1622) to be delivered from Ames. (I have a '68 400) The hi-flow thermostat (180) was on backorder - no idea when it will come in. I'm looking for other options. I checked the Flowkooler Robert Shaw (330-180) on their website but it doesn't list the '68 400 as compatible. Recommendations on a thermostat given I'm installing the Flowkooler (1622)