I've read many of the posts on this site about changing out from a v6 to a v8 but I have one big question. After I get the motor and transmission, what else will I need to buy such as motor mounts? Also I have a custom rear end that has positraction. Will this rear end support roughly 700 hp? I have the motor running 680 right now.

 

The motor mounts will be different between the 6 and 8. The radiator and hoses are different, all the accesories are different, the tachometers are different, and the front springs between the v6 and v8 will be different. As far as the rearend, what exactly does "custom" mean? Is it a 9" or 12 bolt? Then yes it should hold up behind your motor, or is it just a standard 9 or 10 bolt which will not survive behind 700hp.