I know the title is dumb but I can fix most anything on older cars but I can't diagnose things. So, I just replaced the intake manifold and carb and can't get the engine to run. It has msd distributor and I'm getting spark and gas. I did preliminary timing by turning on the key, putting on the timing light, and turning the dizzy to see where is sparks #1 cylinder. But when I try to start the car is backfires either thru the carb or exhaust. I then move the dizzy maybe 5 degrees and try again. I've moved that dang thing up to 1/4 turn both directions until I literally run the battery down to where it won't crank anymore. I'm out in the country so don't have any help, just by myself. Could anybody give me some direction on how to get the timing close enough to at least start and run, then I can make refinements. I know this is very basic and I feel dumb but don't want to damage anything by continuing to have the engine backfire. Thanks.... And Happy Sunday..