my buddy has a 572 10-71 supercharged world block Hemi. wants to put it in a 68 roadrunner.
obviously unchartered areas. will make around 1000hp.
will the 383 k frame hold up with say shumaker mounts?
or will need reinforcements. what will he need?

Yes, to your question. Everything is strong enough for the hemi. You can use aftermarket mounts that will fit, make your own solid mounts as I did or use elephant ears behind the water pump. The elephant ears would make header installation the easiest for clearance. If you use a rubber style mount you can always install a torque strap along with it. I have always used some type of solid mounting system. Just make sure your transmission mount has some type of rubber or spring system to allow for movement, if not you will be braking the tail housing on the trans.

I would use a front motor plate or a set of elephant ears and cut the stock steel wedge mounts off the K member to get more clearances for the headers
The front header pipes on the hemiroid motors MAY NOT clear the stock wedge K member welded on mounts very well
As pointed out make sure and use a stock type tranny mount with any solid front mounts