Thermostat housing options

If that's a Magnum-sized thermostat (not the large earlier LA size), then you could look into Chevy thermostat housings like this one from an early '90s Corvette:
View attachment 1716269822
P.S.- Why did you eliminate your bypass? Just wondering...
You have me, i don't know but I'll ask the builder. I have the Sniper 2 efi which needed an extra temp sensor.