HD or truck could see a hi load on the crank at low rpms the damper would be bigger to help this but if you are not run it in a truck them you could swap them out but most think the big damper mean HP engine gm used big dampers on all HP stuff in the 60/70 small and big blocks but the 454 had a big damper to help with the external balance of the crank it let them put the weight in the hub of the damper and the 400sbc to. to get the mass down a lot of guys run a small dammper to spin up faster i have all ways lean to the side of caution on hot engine or all out races engine not really not knowing where in time or how much harmonic there will be and if the smaller one could help dammpen some of it when it comes. from what i know it can happen at any rpm more or less so a big dammper has more surface to help controll it the oem ring type but still if you want to a small one that they say can do a much better job at it like a TCI rattler or ati then you could run a small one