5.5 head

[Dodge]

Just a side note. Don't use a tap to clean up the head stud holes. Use a thread chaser.
The thread chaser will clean out the threads. The tap will cut material out of the stud holes.
There are three grades of taps. Each one has a different tolerance of depth cutting.
The taps most of get from the hardware store, Snap-on, Matco ect. cut a deeper thread
than the taps that are used in engine manufacturing.

[Model "A" Fords]

[QUOTE=Dodge;2252508]Just a side note. Don't use a tap to clean up the head stud holes. Use a thread chaser.
The thread chaser will clean out the threads. The tap will cut material out of the stud holes.

D.I.Y. chaser... notch a fastener to resemble a pie missing one piece and it will clear the threads without damage.

[JayJay]

Originally Posted by Dodge

Just a side note. Don't use a tap to clean up the head stud holes. Use a thread chaser.
The thread chaser will clean out the threads. The tap will cut material out of the stud holes.
There are three grades of taps. Each one has a different tolerance of depth cutting.
The taps most of get from the hardware store, Snap-on, Matco ect. cut a deeper thread
than the taps that are used in engine manufacturing.

I purchased a set of thread restorer taps and dies from Amazon (https://www.amazon.com/Lang-Tools-25...s%2C805&sr=8-2) and they’ve worked just fine. Not horribly expensive - about $50 if I remember correctly.