could also make a duplicate of the 400TX on D3200 as others have mentioned, actually I think the kodak P3200 is worse but that's opinion. Anyway either way if you dupe it onto D3200/P3200 somehow and push it to 3200 or even 6400 it would certainly be grainy

If you've already developed this film anyway...

IF you're planning to shoot more, two things, one is use the aforementioned 3200 speed films, and second, during development, shake the hell out of it, don't be shy, pretend you want to mess with your friend and hand him a can of soda that will explode.

each "agitation" just shake it, and shake it good...