when you come to fit the cranks, if the bearing cases seem tight, dont fook about - take it to a bike shop
my mate bought some new fc's to go in his nos 85 FST. they would not go in. we had it in a vice and everything.
and dont swing off the pinch bolts when doing them up. we snapped one on the fst, with VERY LITTLE effort.
for my money i would go with the cheaper proline cranks.