Strange electrical problem

Hello all.
I have an interesting problem with my lights in my '76. Crusing down the road at night, I start to see the turn signal lamps light up. They don't blink, rather they pulsate from dim to off. Now, I even have my bright lights doing the same thing. I have no clue where to start because it doesn't seem like a short. All respective lights work when needed: turn signals, high beams, brake lights, etc.
My only thought is the Accel HEI coil I put on the car about a year ago. I had to remove the shielding for it to fit. Could it be possible that the high performance coil is inducing a current in the other wires (due to the lack of shielding), or is there another issue here that I am missing?

Any input would be a great help.
Thanks.

I would look for a bad or loose ground wire. A lot of weird things start happening when the grounds fail. Your headlight ground is the most likely one that has problems, it's looking for a ground through the running lights. Check your engine to ground strap (located near the starter and right side engine mount) and also the frame to birdcage strap (located at the left side of the firewall, attaches frame to the rocker channel). Then there are several ground wire connections at the steel hood surround.

Thanks. That makes sense since I did just have the engine out last year for a rebuild.