ORIGINAL: priedman

Hi Everyone,

I bought an '03 GT last year and it's stock...for now. I have been reading up about these cars and learning tons thanks to this forum. You guys really know your stuff.

1- How much horsepower can one expect to get from the factory 4.6 and still maintain longevity? I have been thinking about putting a blower on down the road but it sounds like the block/lower end really needs to be beefed up to handle the boost over the long term. I'd like to be able to get 350-400 RWHP at some point and am curious what it takes to get there and if the stock 4.6 is worth the build up or should I be looking into something else.
A stock block and bottom end can handle up to 450, so you should be fine, s/c is the best route.

2- How much horsepower can the stock 3650 5-speed handle?
Not sure, ill leave that question to someone else

3- How about the 8.8" rear? I have read they can handle quite a bit before having to be reinforced?
The 8.8 is pretty tough, but unless your plan on running slicks or have a huge amount of hp the stock rear end is good, otherwise upgrade to 31 spline driveshafts and LSD.

4- Would a 5.4 drop right in between the fenders of the GT or would custom mounts/headers/etc be needed?
Ive heard all differnt things about this. Its basicaly the same engine block, but taller. So im pretty sure you can reuse alot, including heads, but im not positve.


Thanks in advance for the help. Sorry for all the questions. I grew up as a Chevy kid (gasp!) but have seen the light. Hopefully better late than never.

Pete (dreaming of a mystichrome terminator....someday.)