The GMC engines of the same period used a similar, but different Thermostat housing where the temp sender was on the driver side. It will bolt right up to the Chevy head. I got one on Ebay years ago and haven't used it. I was going to use it for coolant heating to a Edmunds intake, but I went a different route. Check Ebay and you may find one.
GMC Thermostat housingFound one.
