Temp sender thread size?

[uncle max]

New Edelbrock heads: A buddy is asking what size the threads are for the temperature senders. Says neither 3/8 NPT or 5/8 UNC feels right...

 

[41ford1]

3/8" NPT is the sender thread.

 

[Mart]

For what it's worth, for future reference, Not all are 3/8 NPT. Don't know if it's a UK thing, but my 37 style 21 stud heads (Wartime build or Pilot) are 5/8" UNF. But as far as I know, If the thread is not the one, it will be the other.

Mart.

 

[rotorwrench]

National tapered pipe would be the only standard that would be usable with most types of available OEM and aftermarket senders for a product like an aftermarket aluminum head. The acuracy of cutting a good fit NPT is dependent on not only the correct tap but also correctly tapering the bore prior to the tapping process. If the bore was tapered too large the fit will be loose and too small the fit will be too tight. Hopefully the job was done somewhere in the happy medium range at Edelbrock.