Need your help! Several solutions needed! Water Temp Sender. Heater core

[VwDrvFnd]

So my Nephew Jon and I are doing some work getting all the heater boxes cleaned up on the Ranchero this weekend when low and behold he ask "Hey what this thing hanging here?" I am like what thing and I look over to the driver side fender and to my disgust it's the mother F'in aftermarket temp gauge sender tangled up in some other wires! WTF! NO WONDER THE DAMN TEMP GUAGE WASN'T WORKING!
Wow I have to find a spot to bolt the thing in that will give me a good temp. Where is the best spot short of drilling and taping the manifold? The factory temp sender is in the right location can I tee off of that somehow?



Next the heater core, The previous owner yanked all the heater stuff out of the car except the fan box under the hood. I am assume because of a bad heater core. They gave me a box of extra parts that pretty much has everything new in it for the heater. The Core that came in the box looks good except around the oval shaped lip where the control valve seals to the core. There are a bunch of slots in the lip. I tried to put some pieces of inner tube in between the control valve and the core to seal it so I could pressure test it but could not get it to seal because of the slits. Do I need a new core?

[rmk57]

Could you possibly drill and tap the thermostat housing for the sending unit?

[SkylinerRon]

There is a special seal for valve to core.  B7A 19460 A  about $5.00 from most of the usual vendors.
Goodluck,
Ron.

[Hoosier Hurricane]

Thermostat housing would not be a good location for a temp sender.  Would only read engine temperature when the thermostat was open.
John