86 suburban running rough

I am new to this forum, so bare with me. I have an 86 chevy suburban with a 5.7L 350 engine. I was going to work this morning and I was doing like 60mph and I steped on the gas to pass another car and the transmission didn't shift right away then when it did shift the engine reved real high and shifted hard. And then it was vibrating like crazy so I down shifted and it seemed to be better but didn't stop. I don't know if its something to do with the tranny or the engine. Any help would be greatly appreciated. Thanks

Take her to a tranny shop and have them drive it. It is possible you could have broke a pushrod/rocker arm when you rev'd it "real high", which would put you on 7 cylinders(which causes vibration like this), but odds are that you smoked somthing in the tranny when it engaged.

plus300, I have an 86 Suburban, too. Sorry that I don't have a diagnosis, but I'm happy to say that I've never had the same problem. If you plan on holding on to your 86 for the foreseeable future, send me an email so we can compare notes and share resources. I plan to hold on to mine for quite some time.