Thank you for all the help you have given me in previous posts.
I have a 87 turbo runner W/143k on the clock.

1. This may sound strange but I hope someone may have seen this before--When braking hard my digital dash flickers in and out--afterwards the speedometer, gas and temp still work but not the Tach or the turbo meter (can still here turbo spool so I know it is working).

2.When nailing the gas the car make a loud sound that I think sounds like back preasure? only occurs when heavy on the gas and right before it shifts to the next gear. Easy driving this does not occur. (sorry cant think of how to explain the soud) It is a air sound.

3.Is there anywhere I can get a really good look at a diagram of the vacum system? the one in my haynes and chilton both suck.
How do I tell if it has Cali. emisions?

 

Probably connection / ground related if the whole dash is flickering. I'd start with the connections on the instrument cluster itself. Start, shake, see if you loose connectivity.

There should be grounds on that truck between battery and block, battery and body, and engine (usually head) to body.



I don't know what the sound is that you're talking about. The intake side of the truck is usually pretty quiet. If it's a whizzing turbo sound, that could indicate the beginnings of bearing wear. If you think it's backpressure, you sometimes can unbolt the cat (if the bolts aren't frozen) - run it with the cat disconnected to see if it clears that sound. The converters have a finite life.