The easy way is with the drb, but you can do it without it. The cam sensor switches from 0 to 5 volts, so backprobe the signal wire and watch it with your meter. Then manually put the engine at top dead center on the timing mark. Loosen the distributor and you should be able to twist it and watch the meter go back and forth between 0 and 5. Right at the moment it switches tighten the distibutor, it should be almost flickering between 0and 5. That is from memory, but it does work, I had to do it this spring on my cousins truck and we didn't have a drb. His magnum swap wouldn't start until we did this, but it would start with fuel down the intake.