NOISY Shifting

81 k20 with a 350... when shifting at high rpms, it makes a loud whooshing noise kinda like air is getting sucked in instead of just shifting. Obviously that's not what it is, but the tranny seems to shift with a huge delay. Also the rear end makes a weird noise like it's not hooking up. anything anyone can think of to check would be grrrreat, thanks.
http://image14.webshots.com/14/8/96/9/170489609keoKuq_fs.jpg