Anyone know what the plug size is to plug up the large holes by the filler neck on a Brodix Intake for BBC? Having trouble with one and think someone re sized it.

This message has been edited. Last edited by: SmokinChicken,

1/2 NPT I think

Thats what I thought but it looks like someone may have stripped it out and tapped it bigger.

All 4 holes (front and back) are the same size - sounds like someone messed it up. Not sure but you might check and see if you can find a thread insert - probably an industrial supply house would be my first look.