What size ports do the thermostat housings have to have to work? I found one in Speedway for $34.95, which looks the same as the one in summit, and it says it has 3 1/2" NPT ports. Sound like it'll work? Part number is 805-7134, sounds like Weiand.
That's a great price, it is a Weiand part number too. It is their unpolished housing. You can add a "P" to the end for the polished version.
I stopped useing Weiand because of availablity or lack of really, especially the polished version. I know use only Offenhouser because they are more available.
Both housing have three 1/2" NPT holes in the side. The Offenhouser housing also has one 1/4" NPT hole as well. I enlarge it to 3/8" NPT for the CTS sensor when you get it through me.