450 swinger on 300 w/ 250r shock, what linkage?

[maddmatt02]

ok, i just got my 450r swingarm and carrier and stuff on its way here and am buying a 250r rear shock, just wondering what linkage I need

400ex linkage, 450r linkage, 250r linkage? will they all work and I just get what I find cheapest, any other linkage work? YFZ's or any other on ones I have most options for finding a good price.

thanks