91 1500 Burb 350tbi/700 When I shift from park into reverse and especially drive, the engine bogs down to just above stall, and sometimes dies. When in P or N, it has a higher idle rpm. Rev's drop when shifted into forward or reverse. I think I have a vac leak between my manifold and brake booster, as I can tell an idle fluctuation when I depress the brakes, but its not a big rpm change. I don't think I have any other vac leaks. Many of the lines have been changed in the last year. I'm thinking that the computer changes the idle when in gear and its not the right rpm, or my transmission is not fully disengaging from the crank and its taking a few seconds for the computer to increase the idle to compensate for the additional drag. Thanks for the help brothers.