Boost pressure

Probably have to post the CPL number if you want to know the boost spec.

I'd check the intake manifold and piping near it for a bung you can plumb in to for a gauge.

 

The closer to the turbo the less a gauge will detect and quantify a leak.

 

Best to plumb the manifold pressure gauge in the intake manifold that way it is showing exact boost going into cylinders and like @beastr123 said it will detect any leaks from turbo to that point. There should be a bung plug or two in the manifold to use.

 

Thats the norm. Most gauges only go to 35. Just remember you want to operate them older engines in a way where it will “breathe” less boost means less heat and less fuel used. If you have to peg that gauge to make the engine pull you got it working way too hard.