Hey guys I recently purchased a bone stock 2003 GT Auto, with 100,000kms on it. It's time to giver her more power. My question is, how much HP can the stock Auto tranny hold on these cars SAFELY to keep a healthy life. Or would going with a performance Valve Body, which ups HP ratings, plus "increased lifespan of the tranny" be worth it! Any info is appreciated!

 

For the bolt ons you listed in the other thread you stock trans should be fine. A custom tune will help as the shifts will be a little firmer but there are tons of upgrades you can do to them for better performance.

 

It will even hold the power of a stage II CAM?

 

I don't see that being an issue. I'm sure there are guys running forced induction on the stock trans without issues.

 

But I also read a lot of blow trannies on forced induction! It just scares me being a 100,000 kms, daily driver. If all my plans work out anyways, I might as well buy an aftermarket valve body anyways, make it stronger, and also a heavy duty tranny cooler!

 

You should check out Muscle Mustangs, they have been building a 2000 (i believe) Silver Mustang GT automatic. If i remember correctly, they were doing heads, cams, exhaust, built auto trans, gears, suspension, ects....

 

Sweet find! It's a 99 silver called silver stealth stang! I mean there car had a load more miles (160,000 MILES) but basically with most the mods I named, (except they had shorty headers and Im getting long tubes) Most of the mods are the same, minus the CAM and a few others, they put down 234 rwhp and 272 rwtq. Not huge, the cams would help with a round 35 HP/TQ more, but they are talking about how to get this to the wheels better from the automatic! Real interesting find 03GT! Thanks! What are the numbers your putting down? Or last you knew anyways.

 

That's it, i could not remember what they called it LOL!
My GT put down 298 hp and 308 foot lbs of torque.
That is with....
JLT true cold air intake
ported 2001 Bullitt intake with a '98 Cobra throttle body
VT/Cushman Stage II N/A cams
Steeda pulleys
Bassani catted X pipe
Flowmaster 40 series originals cat back.

 

Wow that is way better, I actually read there up to date article, with the bolt ons I named, upgraded tranny pieces, and some better drivetrain purchases they were up to the same as you as well. So it looks like i'll be putting down around 300HP Im so glad!

 

Your goal is achievable for sure!!