Thanks for the replies everyone. I am 99% sure that it has the correct type torque converter (it has two weights) for the engine. It was raining last night when I got off but I will get under there to verify it as soon as possible. I have this harmonic balancer
https://www.summitracing.com/parts/sum-163318/overview/make/dodge , which I believe is correct. I would have rather had the ATI harmonic dampener but the funding just wasn't available. There was nothing wrong with the stock balancer, I put this one on troubleshooting the vibration.
The flexplate v8fish mentioned above is for a 360 and a internally balanced converter, which B&M plate is correct for a 360 and an externally balanced converter in a 904?