I'm just starting in on my 3rd. The 460 is a nice swap because it was an optional engine in the F-series trucks so it's pretty much a bolt-in. You can easily build the engine for almost an horsepower level you want & even with a basic/mild rebuild you're looking at an easy 400+ HP. The stock bottom end is good for 600hp, above that you need to start looking at main stubs & maybe a stud girdle.
As JSM noted, figure out what you really want to do with it first. If you DO a lot of mudding then it's hard the beat the HP & torque numbers a 460 can crank out.
My last two 460's were just basic performance rebuilds, the better of the two dyno'd out @ 430hp & 470lbs of torque. This time around I'm going with a stroker. Going with a 4.39" bore and a 4.5" stroke nets you a 545 and that's with only a .060" overbore. Kits (crank, rods & pistons) run about $1200 so you can build it anywhere from 502CID to 545CID for very close to the cost of your standard performance rebuild.
L&L products has complete swap kits that include motor mounts, oil pan, headers, oil filter relocation kit (only needed for 80-96 Broncos) and all the accessory brackets & hardware. The L&L kit makes the swap am effortless bolt-in. You *can* do it cheaper by scrounging factory parts but the L&L kit really is the way to go. I particularly like their fenderwell headers, getting the exhaust out from between the framerails make a big difference when you're under there working and it makes running your own exhaust *very* easy, no custom bending.
We were just discussing this recently in another thread & I posted an interesting article on stroking the 460 out to 540 using a collection of factory parts. The article is interesting but not necessarily relevant since it was written before the cheap Chinese crankshafts became so common.
http://broncozone.com/forums/index.php?sho...&hl=stroker
http://www.landlproducts.com/default.aspx
There are a couple other things to consider as well. Depending on what/who you go with for your swap parts (motor mounts, oil pan, headers, etc) you'll want to make sure you get as much info up front before committing yourself to engine/parts purchases. Both my 460 swaps used Lincoln engines and that led to some complications/additional expenses. The first time 'round I used factory 460 engine mounts and L&L's fenderwell headers. Unfortunately the combination didn't work out so well because L&L's mounts locate the engine a little lower than the Ford mounts. What this meant was that with the Ford mounts the header collectors would rattle & bang against the body mounts, a problem made worse by my cam selection & the lumpy idle it generated. A little bending & tweaking cleared the driver's side but I wound up having to notch the passenger side body mount to make it work. Also, using a Lincoln engine forced me to relocate all of the accessories. Again, the first time I tried getting away with just redrilling & spacing the 351M/400 bracketry but I never could get the belts to run true and ultimately I broke down & bought the L&L brackets which worked great. However by buying all my parts piece by piece I wound up paying more than I would have of I'd just bought the whole kit outright (which is what I did with the 2nd swap). Now I'm not sure just what the differences are other than accessory location but LMC Truck also sells engine mounts for this swap and they have a notation that they won't work with Lincoln engines, now as far as I know the motor mount bosses are the same on both Ford & Lincoln 460's which would mean the accessories are probably the issue. To try & make things easier on myself & my wallet this time I'm using a 460 sourced from an E350. Hopefully the front dress on this one will work without modification, it has the much better Saginaw power steering pump and it also has the rear sump oil pan, so by using the van as a donor I *should* be able to get away with just getting the motor mounts & headers from L&L and that'll be it.