Re: 67 HEI big block will not run
LEAVE THE SPARK PLUG GAP TO .045, NO NEED TO CLOSE IT DOWN.
Plugs dry/clean, or wet, black?
Voltage test from feed wire into HEI, disconnected from BATT terminal, to engine ground, volts in BOTH START and RUN? Run will have more volts than start, as start also runs starter motor,for significant volts drop reading.
Your procedures for finding number 1 firing and initial set of distributor were right the first time. Finger in plug hole, pressure build, hand move crank to attain full TDC, check lines on balancer/scale for accuracy.
At this point, you would need to confirm TDC lines up with zero on timing scale. To do this, I usually use a small screwdriver through the plug hole while HAND ROTATING the crank with socket and breaker bar, to "feel" the piston come to the top of its stroke. I then can confirm/deny the TDC interface on the balancer is correctly aligned.
Install dist with rotor pointing to the terminal you wish to use as number 1 on cap. Then, remove the rotor and on the large HEI, you will notice on the magnetic pickup, 8 inner and 8 outer 'spikes'. Line the closest spike set up0, lock dist down so it can be moved, but not so loose it moves by itself.
Reassemble rotor and cap, make sure feed wire in place, try to start engine.
If no spark, remove feed wire from dist BATT term, jumper wire BATT on dist to positive post on battery, try to start engine again, if starts, problems with feed wire, no, distributor issue.
Now, also check the IGN or IGNITION terminal on the fuse box inside the cab, full volts at ignition switch RUN and START. If good, run 12 gauge wire from that post on fuse box, to BATT (but, assuming the old HEI worked correctly, the feed wire that is there now may well be OK, or, could have issues).
Changing the feed wire from the bulkhead connector to the BATT terminal is a waste of time and butchers up a perfectly good wiring loom, and just isn't needed.
If the IGN term does not have power in start, post here, and we will describe alternate method, but, it shouldn't be needed.
One common problem with the large cap HEI's is the coil grounding. Of the 3 wires between the dist and cap, the center is the ground wire for the in cap coil, and MUST be clean, and in place. The coil is screwed down into the cap with 4 screws, and under the coil there is a Buss bar from the center of the 3 wire feed terminal, to the underside of the coil. The coil itself also has a ring terminal that goes to one of the screws, to ground the coil. All must be correctly installed, clean, tight.
Also while coil is out of cap, ensure the correct install of carbon post, insulator, coil. The correct install is bare cap, carbon button with spring pointing upwards, insulator, (ground Buss bar in place as well), coil.
The single most largest failure issue on large cap HEI's is the HEI module, but, NOT because the modules are failure prone, but, because coils layer short from all sorts of reasons, and over work the modules to failure. Usually, the coil is the last thing to get checked, because persons tall others "it is that module that is the problem, you need a (fill in the blank "racing" expensive one). NOT SO.
If there is a problem suspected with either a module, or especially, the coil, take them off the distributor, find a parts store that has a run tester, runs them OFF the vehicle, and let them run to get hot on the tester. Replace shady/doubtful/dead parts. NOTE: resistance tests of modules and/or coils are NO LONGER WORKABLE, no matter whom says different. RUN TEST IT.
Magnetic pickup coils are also problem prone, in the connectors at then ends of both feed wires to module connector, and they fail. A resistance check from each terminal of the pickup connector to the other, while moving the wires should show an intermittent wire connection in the pickup wires/connector to module. Resistance for the HEI pickups is 400 to 1,100 ohms, Rx1 scale. Should have NO continuity to ground from either sire.