That was the block C8VE-B

 

What is done to your truck right noW.
Then we can suggest parts.
If you want 400hp then you'll need to spend some time and money.
Pull the heads and port them. It's not hard. But stock heads won't get you much past 350 with today's fuel. Like I said before, pull the valves and you'll see most of the issue. Performer or perf rpm intake. The regular performer will need a spacer. Buy the 4hole to two hole blended spacer. Do not us an open spacer.
Cam is an off the shelf crane cam... But I can't remember the number. I'll have to look it up after work.
After porting the heads go get them cleaned and shaved about .050. Not sure what the max is before intake fits funny but .050 is ok. This will bump compression a little. (assuming you are leavi g the stock shortblock alone)

That will give you an honest 350-400hp and 550 torque.
My last 460 made 450+ hp and almost 600tq and wasn't much more then the setup I said. And I even used a performer intake so I had awesome low end responce. You'll want a 700 double pump or a very good tuned vacuum 750.

 

Manual trans for a truck....that's not a truck trans. Hmmm
Nope
If you had a 2wd you could have found a toploader (t10 I think) that would bolt to a regular manual bell housing. But being 4x4 you'd need to run a divorce mount xfer.
Hmm
The zf5 I've offroaded with and wasn't bad. The old original 4speed took some abuse. I use to race people all the time. It shifted slick. I blew up the sterling 10.25 diff on a no-lift shift into 2nd gear with 33" tires. Then same truck (put a d60 rear in it with Detroit locker) I broke both axles (2 separate times) once was a powershift into 3rd and once I had 40s on it.
You just need to be more serious about shifting it then a car. All the transmissions you'll find that bolt to a 460 will either be a truck trans or shift like crap. I've never had a nice shifting toploader in any of my 60s mustangs, and it bums me out.

 

Well I won't be running anything larger than a 32" tire. I have a zf 5 speed from a diesel, what do I need to changeto make it work on a 460. I'd even consider putting a aluminum head on it later on. But I want to make some power cheap and fast. Without doin much morethan a cam intake carb and maybe rockers.headers and dual exhaust

 

I thought the idi trans interchanged. But the "powerstroke" engine is different.
Measure the bell housing bolt pattern. If its the same then I'd use it. The diesel has a higher 1st gear which is nice. I hate the granny low in mine. Useless. I didn't like it in my 4speed and sure don't need it.

 

Well it is an idi tranny with a brand new clutch so I was hoping I could use it. Does anyone know if it's possible

 

The IDI and 7.3 powerstroke trans are the same bolt pattern. I have seen 460 ZF5s used in diesel, but never a Diesel trans used behind a 460. Dont know if it can be done

 

the dump truck trannys work great for rippin, but ya have to swap out the rear gears accordingly (i run high 12's/low 13's with my nv5600, stock 3.55 gearing). a properly setup rear will give you the "sports car" rippin ability you are lookin for. if you have the dough, a 6 speed conversion would be the ultimate best, but outrageously priced.

zf5 w/ a rear end re-gear is probably the best all around solution for cost/effectiveness. there is plenty of room on the top end of 5th for the re-gear (rollin on the highway wont be so miserable, especially taking into consideration the copious torque of the modded 460), so dont be too concerned about that.

 

even if it was possible (im pretty sure it's possible with the right part combo), it wont hold @ 350+ hp for very long, if at all.