thanks scott. I guess that's the one you can use for the power brakes. I've seen as well fittings that you can buy in case you go for powerbrake. thanks for the info about the thread. National Pipe Thread and inches of vacuum make me laugh (i'm a metric european), but I'll google for its size and go to a plumber.

I'm going to check on my compression after new year, so I'll throw this in as well :-)

Kalli