Outer Limits 4x4 Board

Does anyone have any recommendations for the exhaust size on a 4.6l. I was going to go 3", will this be too big. I was reading somewhere lately that one of the biggest issues with a big v8 is getting the exhaust gasses away but I also know that you have to have sufficient back pressure, especially on the Rovers.
Also I want that big meaty sound again. The current (broken) exhaust is 2.5" and when it was hooked up to the 3.5 it really growled but with the 4.6 it is a lot quieter.

twin 1 3/4 cheap as chips and it'll sound better than a single system to

I run a 4.6 in my defender with extractors down to a single three inch, through a hiflow cat then a cheap arse muffler all remaining three inch mandrel bends .Runs and sounds great people offen come up to me and ask what im running they seemed shocked when a tell the its a rover 4.6 it is quite loud i must admit

Thanks all, it is booked in to get a 2.5" mandrel bent exhaust installed next week. I did want 3" but Performance Exhaust in Ringwood reckoned it would be too big so I'll listen to the experts. I thought the current exhaust was 2.5" but it was only 2".