I'd always thought that the 250/465H upper legs were as long as the G parts, but I'm beginning to think the shorter type, as fitted to the J+ models
(and, if the H parts are as long as the G ones, then I'm f$%ked if I know what I've got on my bike!).
If they're shorter, then you've got no drama.
That said, it seems that 95% of Evo Yamahas are running the later forks with the horizontal brake lug, and/or external dampening adjustment. Nobody's ever seemed to care (even on this forum!), so I can't imagine a too-short set of upper tubes being a drama.