I am looking at a 4.6L, fresh rebuild with new rotating assembly (it is a 97 mustang GT), it has a PI swap done to it so the pi heads, intake, etc, it is all ready to bolt into my mustang. Should be getting around 340-350hp?? What would you say this thing is worth?? Thanks!

 

What else has been done to it to get 340hp? Is it supercharged? It probably has more like 240-260hp

 

Well i think they have that stock, and the addition of the PI heads bring the compression way up and i believe are supposed to give it an additional 80-100hp. I remember reading a buildup in hot rod when they did this and with the addition of their cams to this combination it made 400hp.

 

You will have to run at least 93 octane fuel with the higher compression. @ well over $2.00 a gallon, that would be aweful costly for a daily driver.
The head/cam swap to PI heads is worth about 35hp. That put the 99GT up to about 260hp. The DOHC Supercharged 03 Cobra only has 390hp so I would think that the engine that you are looking at is probably in the 280-290hp range.