Navarro 8ba Heads

[KiWinUS]

Originally Posted by Tim Ayers

It shouldn't be "hanging out" but it also shouldn't be tuck deep inside the threads of the head. If they are off the engine, you can get spark plug spacers to help you select the correct one so you can use common 3/4" reach plugs.

Now that I say that, are you sure they weren't reworked for 3/4" plugs? New Edlebrocks are recast this way.

You can even use an extended tip plug in the new Edelbrock even with .400 valve lift and heads cut for .045” squish.