4.6 engine and tranny rebuild cost
 

how much would it cost to get the engine and tranny rebuilt in an 03 gt stang

You'd probably be better off finding a decent engine and trans to swap it out. Would be a much cheaper route.

but you dont know his goals. he may want to add boost to his car and have high power numbers

as for your question, go to modularpowerhouse.com and check out theyre build shortblock. they are a very good shop and i know that they have a lot of extremely high horsepower 2v cars.
600hp Shortbock (the lowest model they have): $3k


as for the transmission, if you need to rebuild it you might as well upgrade it to the T56 if you have a manual. even if you ahve an auto and want a manual, now is the time to do it.

T56 from D&D Performance: $3200

if you just need a stock engine and transmission, just go to ebay or mpsautosalvage.com

not sure what type of tranny you have, but I just blew mine. I talked to Darrin over at BC-auto and I am going to go with a completely built racing auto tranny capable of holding 600rwhp and a 3500-3800 lock up converter. All you have to do is swap this complete package in and it'll be good to go. $3k shipped