i think some folks just are lucky. when i did my SFI damper, it would not even begin to slide on. i could barely stick it on the end of the snout (by hand). and it was on, even like that. i have read that Romac's are also very tight like that.
after talkin with Michael and Rick when i did it (thanks to both of you), i was loaned a puller and installer by CSK (i decided that it was necessary). it is free, so i figure why take a chance on messing up the crank threads. with the install tool, it threads into the crank and so one is not trying to seat/slide the balancer on with a thread or two of threading. i would have had to beat the balancer (or heat it up, which i would not do) to get it on far enough to even begin to thread the bolt in. not cool.
of course, for you guys whom had dampers slide right on, this is not necessary. but if there is any resistance, i highly recommend using a (free) install tool. why take a chance? BTW, the damper instructions that came with mine said it should not slide right on - if it did, return it. i dont know if such a tight fit is normal, but im glad it fit so snug (and glad i used never seize on it).
good luck.