I would start by making sure the distributor is properly timed. Base timing for the HEI GM distributor is set as follows:
1. If this is computer controlled advance, disconnect the tan and black wire between the distributor and the computer. If this is vacuum advance, you don't need to disconnect anything yet.
2. Turn the crankshaft to align the timing marks at the correct position for this engine. If timing is supposed to be set at 10 degrees before top dead center, that is where you position the crankshaft.
3. Remove the distributor cap and verify the rotor is pointing at the number one spark plug tower. If not, reposition the distributor or realign the plug wires to match. If you pull the distributor, you will need to align the oil pump prior to dropping the distributor back in. You can usually do this with a long screwdriver. Also verify correct plug wire positioning on the distributor. The typical GM firing order if memory serves was 1-8-4-3-6-5-7-2. Cylinders 1-3-5-7 were on the driver side, even cylinders on the passenger side.
4. With the distributor and plug wires properly installed and with the distributor clamping bolt loose. Turn on the ignition key and turn the distributor while watching for spark at the number one spark plug wire. When the spark occurs, slightly tighten the distributor hold down bolt. This should set ignition timing close enough to get the engine running and allow you to accurately set the timing with a timing light. You may have to turn the distributor fairly fast so the pick up coil generates a viable signal for the ignition module to react to and command spark.
This all depends on valve timing being correct also.
Good luck.
1. If this is computer controlled advance, disconnect the tan and black wire between the distributor and the computer. If this is vacuum advance, you don't need to disconnect anything yet.
2. Turn the crankshaft to align the timing marks at the correct position for this engine. If timing is supposed to be set at 10 degrees before top dead center, that is where you position the crankshaft.
3. Remove the distributor cap and verify the rotor is pointing at the number one spark plug tower. If not, reposition the distributor or realign the plug wires to match. If you pull the distributor, you will need to align the oil pump prior to dropping the distributor back in. You can usually do this with a long screwdriver. Also verify correct plug wire positioning on the distributor. The typical GM firing order if memory serves was 1-8-4-3-6-5-7-2. Cylinders 1-3-5-7 were on the driver side, even cylinders on the passenger side.
4. With the distributor and plug wires properly installed and with the distributor clamping bolt loose. Turn on the ignition key and turn the distributor while watching for spark at the number one spark plug wire. When the spark occurs, slightly tighten the distributor hold down bolt. This should set ignition timing close enough to get the engine running and allow you to accurately set the timing with a timing light. You may have to turn the distributor fairly fast so the pick up coil generates a viable signal for the ignition module to react to and command spark.
This all depends on valve timing being correct also.
Good luck.