Yeah...?

A lovely potato for you! (because I don't know the answer to your question).

a little over 300 for the transmission?

I'd say probably somewhere around 300, even as much as 350, but probably not much more than that. The 4T65E transmission strapped to most 3.8s, even the s/c'ed ones are fairly beefy.

Over 300? Good to know. Thanks.

is it the hp or the torque that will have the greatest impact on the tranny? it already has 280ft-lb!

Truthfully you make the most horsepower at high-er rpms, and since the transmission has to spin normally 3 times faster to transfer the power from the engine to the ground, when its spinning about 4 grand, the transmission is spinning about 12......so I'd say that the torque would be worst to the axles and differential portion of the transaxle, but the high-rpm would be more harmful to the transmission.

About 340, I think.

These things can take a lot of abuse...

Speaking from experiance, my transmission could only handle about 320ft lbs, and 280hp, then 3rd gear started slipping and I had it rebuilt with kevlar clutches. When it went bad, all I had done to my car was a reprogrammed computer, and a smaller pulley. The engine itself can handle alot more power.

Not sure about the transmission but the engines can handle quite a bit, with out to many mods.

One of the places that offers mods (www.zzperformance.com) has turbos and intercoolers available.

One of the Grand Prix's I saw on there was making over 600 hp.