looking to change my 4cyl for a chevy v6 or v8
 

I want to change my 4 cyl. out with another engine but havent decided on which one. I heard that its not that hard for the chevy v6 conversion. I know there is some changes to do to the engine compartment for the v8. I was looking for feedback on what other people have done and want to see what would be maybe easier or the best to do. Thanks in advance

Chris