And dont forget that the ECZ G should be the large font castings if they are going on a Bird

Oldmics

Most T-bird parts suppliers list the bushing for the '57 as well as the '56 - just order up the correct bushing. Someone must have previously put that one in there in order to use the heads with an earlier sender. 

 
 Steve Metzger       Tucson, Arizona

They are stamped ECZ-G.

Are you sure those are the correct heads for a '57?  The threaded bushing seems to be the '54-'56 size, 3/8" NPT.  The '57 sender is 1/4" NPT.  The heads should have ECZ-G as the casting mark for a '57 E series.  Actually all '57 engines had G heads from the factory.  Since you specified E series, I assumed it was a '57, since that was the only year for an E Y block.

John - "The Hoosier Hurricane"

Thats correct as in picture, its for temp sender

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

In the process of restoration of an E-Bird, we had to obtain the correct heads.

After the heads were rebuilt I got a call from the mechanic asking which side the threaded hole go.
One head has smooth holes in each end, the other head has one threaded one plain.

It appears that one of the heads has a threaded penetration into the waterjacket. Is this correct?

Thanks again

dale@ndt-inspection.com