I have the iso grips on my t-bird, they are the same grip as fits the america/speedmaster, which are 1 inch diameter bars. I think they are the same as fits the honda magna series bikes as well.
one thing I noticed (and it may just be my pickiness) but the iso throttle grip has some end play in it that I thought might add to vibration, so I cut the stock bar end down and left it on the handle bar to take up the space. it felt much better, no slop.
Did you have to replace the throttle sleeve as well or will the grips install over the stock sleeve? Thanks.