Hello My 68 chevelle is having a problem with it starts fine idle is a little high but everytime i throw it into reverse or any other gear it dies. I had an at home mechanic look at it and everything he said it was a vacuum leak maybe or there is a little coil that sits right next to the carb I am not that engine savvy I know body work but Someone please help

had a similar problem,it turned out to be the sparks plugs they didn't look fouled but they were.New plugs gapped to .40 ,the cheapest fix.

Sounds like a vacuum leak to me. Disconnect and plug all the vacuum ports on the carb, and intake and see if it still does it. As for the spark plugs, it's worth looking at, but only gap them to .40 if you are running an HEI. Points types need .35.

Shawn