Rocky,
The boost gauge you purchased should have come with an install kit, which probably includes a thin teflon or plastic vacuum line, and a union for near the manifold.
The plastic line will get snaked thru the firewall, through one of the existing grommets. I forget exactly what is over on the driverside, but there are grommets to use.
Its a matter of getting it through the firewall and then fishing it up into the dash. Have some stiff wire or a coat hanger on hand to help fish the vacuum line - its a bit tedious but not really difficult. No need to disassemble the dash. You could find also, that it would be more efficient to start at the dash side, and work your way into the engine bay. I've done both ways.
Be sure that if the vac line comes thru anywhere near the pedals - that it is not going to be crushed or kinked by the action of the pedals.
Hope this helps.
-Rocket
