Because of the front cross member on my 65 nova, i have to use a 6" balancer on my 327 sbc. I just got my hands on a racer brown 406 that im dropping in but the issue im having is the harmonic balancer on this new engine is a larger 8" that will not fit and will rub against the front cross member. Do i need to go out and buy a new external balanced 6" because of the 400 external balance setup or can i just buy an external weight and add it to my current harmonic balancer that already fits? i've already purchased the external balanced flexplate. Thanks in advance. any links would be helpful.