So I took my car ('72 Duster) to a local car show a few days ago. The car started up and RAN FINE with no issues at all, on the way to the show. After show was over,
I started the car up, let it idle till it got to about 140-150 degrees, as I always do. When I left the showfield and got to the main road, I shifted gears, (it has a forward pattern manual valve body)...and once I started to shift into 2nd gear at 35-37 mph..all of a sudden car made a loud "POP"!!! noise, and it completely died, lost power steering, and had to quickly pull into a nearby parking lot. The noise from the car sounded alot like a loud fire-cracker going off!

Now... there is no electrical power at all,...no interior lights/headlights, although the electric fuel pump still runs when I turn it on. And I checked battery, (Optima Red Top gel style) it holds a charge. Engine is a 340 block stroked to 418 ci, with a solid mechanical cam, and adjustable 1.5 Indy roller rockers, an 850 cfm Demon chokeless carb, single plane Edelbrock Victor 340 intake. I am at a loss here...any help would be appreciated!