harmonic balancer 318 differences?

Hi, I am new here.

I had a coronet 440 station wagon with a 318 cid engine (mexican version 4V) This is the question: I am making a complete rebuild and the mechanic tell me that I have to change the harmonic balancer. I was looking in the internet and I see in the catalogs that are different models (69 and older, 70-72, 76-up) and the prices change a lot. My engine is a 1968, it had forged crank I think but I donĀ“t know if it was replaced or no, and in this rebuild I will use aluminum pistons with dome because I will put 1975 heads to preserve the compression.

Which harmonic balancer I should buy? Thank you a lot for your answers
Author: jormymex74