Well, I went out and played with the vac line and did some driving and I have to tell you, it runs a LOT cleaner in the low to mid range with the vac line hooked up and working.Since I don't run pedal to the medal much (i'm a crawler-what can i say) the difference is very apparent off idle. Fortunately, it appears on this new SR (to me) that someone already replaced the plenum as everything is tight, no apparent airleaks etc. Has 122k on it. One thing that I DO have tho, is an intermittent clicking from the passenger side rear cylinder area. Sounds like a lifter not being fully pumped up, but it comes and goes. I wonder if that hydraulic lifter back there has some crud stuck in it. Going to do full engine flush with new oil tomorrow so we'll see if that solves it. Otherwise rest of truck seems to be working great, so guess I got lucky again.