The Tranny will be fine as long as your Torque is under 400. The Engine block durability is measured by how much HP you have in the car. The Tranny's durability is measured by how much TQ you have. Upgrading our stock tranny's might cause morre problems. You are better off getting a new tranny, that is a 4SPD and can handle the TQ.

 

Again,I'll say 500. We have 320torque right now and it will easily surpass 400-450.

 

Mine has been fine so far for 22K miles, and I'm running about 430 flywheel hp. I'm thinking of going with smaller pulley and custom tune though, to put me at probably 475 range. Not sure I want to do that if it's gonna cost me a transmission.

Does having the 3.73 geartake some of the load off of the transmission?

 

Well, contact the mfg of the Tranny, they'd no better.... That's where I get my info from.

 

can 5speeds handle more? i guess i can DD a manual again.

 

Brent killed his 5R55S tranny last year with his first built motor.
I know this because he tuned my car and my Level 10 transmission and we spoke at length about this. He replaced it with a 4r70W from Lentech.
If you search you will literally find dozens of people who have had their tranny go out after getting forced induction. Some people are luck and it holds up but there is definately a risk of failure above 450 HP.
I chose to upgrade to a Level 10 Stage III because I wanted to keep the stock 5 speed tranny and keep it managed by the PCM.
I have pushed as much as 523 RWHP through it and it has been solid as a rock.

 

Very nice. Gerry,is your GT still put away for the winter? We should meet up again in spring, like last time. Should be fun in better weather.

 

5 speed what? I have a 5 speed. Autos can always take more than a manual.

 

i don't think so man. A manual with forced induction can handle the power with an upgraded clutch. The auto's seem to break down with 450hp. Most guys seem fine with 450 at the wheels on a manual.

 

Since you're upgrading the manual, why not compare apples to apples. Historically, autos are tougher.