Hey guys, here's a question for you. Just bought a GM 350/290hp crate motor and the balancer ( which is not included ) the dealer ordered for me measures about 6 3/4" in diameter. My old motor had an 8''. My question is how is the balancer size determined ? The parts guy said it's sized by the car, in this case a 72 Nova. Doesn't sound right to me.

It does if you'd like it to clear the front sway bar. Different chassis have different suspension components mounted differently car models.

Return the 6 3/4" and keep your old 8". The old one will work just fine if the rubber looks to be in good contion. :D