So last night, I was driving home on the freeway about 68 mph with the cruise on. It was probably running around 2800 rpm. Out of nowhere, the rpm spiked to close to 5500 before going back to a normal rpm range. I noticed that after that, almost immediately under acceleration, it seemed to shudder. I checked the boost gauge, and it wouldn't go past 10 on the vacuum side. I can no longer hear the whine of the S/C either. I was able to drive the truck the approximately
4 miles home after the incident, and it started fine this morning, though I didn't drive it. I did however leave it in neutral and gave it a bit of gas, and the same thing, it won't boost or go past about 2400 rpm without shuddering like it air starved. Any ideas on what this could be and what it might cost to repair? I have the original intake manifold I got from the second owner (I'm the third), so how difficult of a job is it to swap the S/C out?