1978 Chevy Nova Could my distributor have jumped time

I have a 78 Chevy Nova with a 305 i've done a lot of work to recently and im all caught up on its annual maintance new waterpump, spark plugs, wires, distributor cap, rotor switch, coil, alternator, battery, oil change, tranny flush, timing chain and sprockets and so on and so forth, so I installed an edelbrock intake maifold and 600 cfm carb, I was haveing a problem with the car running rough so I loosened the distributor hold down bolt thinking maybe I didnt get my marks I had but on there when I put the intake manifold in lined back up exactly where they were, so before I could fire it up and start adjusting the timing I noticed a vaccuum leak around the carb seat and I fixed that( one of the studs was real loose) so I fired it up and it ran great but the idle was high so I got out of the car and started adjusting the carb to its factory specs, no sooner than I fixed the idle than the engine started sputtering and died before I could get to fine tuning the distributor timing, so I cranked it a few times it fired but didnt start and now it does fire at all but its getting plenty of fuel and air and I have the distributor housing lined up where it was, is it possible that the distributor itself jumped timeing when I was tuning the carb? Seeing how the hold down bolt and clamp were loose. This is all I can think it is cuz I know everything else is good.