ok well found out were that hose went looking at the Virtual Tour of a 2G DSM Engine Bay and it went to the Fuel Pressure Regulator...and i was wondering if i need to connect that tube back...i has a upgraded B&M CommandFlo Fuel Flow Modifier ....would it matter if that tube is connected to the Fuel Pressure Regulator

 

The first pic with the tube just dangeling there goes to the stock FPR, that little brass looking diaphram that is attached to the fuel rail. That clear tube goes to the boost gauge.

 

Well, where is the B&M getting it's vacuum source from if the solenoid has one source dangeling and the one from the manifold is connected to the boost line?
Why is the solenoid's line just open, with a line from the manifold still connected to it?!

 

well that b&M has a little thing on top of it like the stock FPR for that hose

 

Silver coupe is absolutely right. You need to leave the solenoid plugged in electronically but the 2 vacuum lines can be disconnected with no problem. Thats the same story with the majority of the evap sensors as well. The Fuel pressure regulator solenoid can be disconnected as well. I wouldn't recommend it however because it opens up the regulator upon start up to aid in cold starts.

 

Ok, you don't have to have the b&m connected to the fpr because you have a larger fuel pump, so vapor lock won't be an issue....or, you can leave it connected like it shows in the 2G virtual page. I've done both and I don't see any difference in hot startups. I have a 255 also.
To answer your question though, yes, you do need to connect a vacuum source to the b&m whether from the solenoid or straight from the top vacuum nipple on the intake mani.

If you do decide to bypass the fpr solenoid, it needs to remain electrically connected and the tubes removed, just like the boost solenoid.