Ive seen those! I really want to talk to someone who has done it to see how much of a PITA it is lolI know that Adam Brunson at Tune Plus has two different short blocks available for the Mustang. His "A" shortblock is rated up to 500whp and his "Z" shortblock is rated up to 600 whp. IIRC Tune plus will only go to around 400 whp on the stock block without aux fuel on an E tune.