Turn a V6 into a 5.0/5.8??

gotta love the newbs...guess everyone has to start someplace

even so, if you want it to be right and not a hacked up mess...either get ready to spend a few times what the car is even worth...or save yourself the money and work and buy a V8
 
If your heart is set on doing the swap, find a totaled V8 car and scavenge parts off of it. Otherwise, you'll probably end up nickel and diming yourself half to death with miscellaneous parts.