[Stinger]

How big can i go before i have to bore into it??? Also what is the stock size??

 

[MagerThom]

You can go...

70mm no problems. No point in going to a larger TB though,unless
you do some serious mods to free up your 4.6's breathing...
like PI heads and true dual exhaust - waste of money
otherwise.

You're better off going to an 80mm GT MAF and a Dennis
chip - 'til you do domething about the breathing...

 

[The Hitman]

I wouldn't go with a TB until I had an aftermarket MAF. It really makes little difference.