Hi Guys, I have a 1987 firebird with a 305, 5 speed manual. At certain times it will back fire badly and I can't even barely touch the gas w/o it dying. I just limped it home at 30 mph in 4th gear while just barely touching the gas pedal. One mechanic told me that the distributor was getting too hot and the springs were expanding too far and it couldn't keep it's timing. Another said it was vapor locking. It's carbureted and I don't know what the heck is going on. HELP!!