Back of 2 piece intake to the brake booster...

[smdandb2]

What size is that hole on the back of the 2 piece that feeds vacuum to the brake booster? The previous owner of my SL used that as the source for the vacuum block but the 90 degree swivel adapter he used sheared off yesterday.

I am thinking its 3/8NPT, but I want to be sure before I start ordering up some Earls fittings. I know the rest of the fittings on the block are 1/4NPT.

Here is a picture of what I am looking at. In the green are 2 1/4npt, but there was an adapter in the intake itself to allow the 1/4npt to thread on.



Thanks.

[smdandb2]

I am now fairly certain it is 3/8 NPT, so I guess I answered my own question.

[turbovanman²]

3/8 pipe thread.