What in the world do you want to do to a T56 that costs $6000? You can buy a new in the box T56 Magnum for just a tick over $3000.

I wish my T-56 car had an auto.
My last Camaro had a Turbo 400 & it drove great. It was bulletproof, never missed a shift, easy to sit in traffic, and was just better all around.
I would love to convert the current car to a 6L80E.
I don't hate driving the 6 speed, but there's no real love either.
This is a streeter, no race duty. I'd love to take it to the strip, but am afraid of breakage with the 6 speed if I had any traction. I wouldn't worry with an auto.
That all said, I wouldn't dare to convert it because SOMEDAY I will want to sell it, and the 6 speed will make the car worth more. How much more? Good question....

Just my $.02.

Bill

Well I'll need a clutch, bell housing, clutch/brake pedal, clutch fork, throwout bearing, shifter, crossmember...would you like me to keep going?

$6000 is honestly conservative to swap from Auto to manual when going to a T56 mag, hydro throwout and doing it correct.

Does anyone know an idea of 4L80E pricing built to handle 650ish max HP vs a 2004r the same?

I will never take this car over 650 NA horsepower. Maybe a 100 - 150 shot of nitrous for fun on top of that but IN MY OPINION over 600ish HP you give up more than you gain for an all around type car. That is my opinion..yours may differ :)

Stock 4L80E with a TransGo HD-2 shift kit upgrade has been used for many years on cars making under 1000hp. That trans will probably suck up a few HP due to parasitic drag.... but you won't need to worry about giving it a nice thrashing.
They make Tbrakes for them also. Jake's is a respected builder.... as is Rossler, Mike's transmissions, etc.

Just do some google searching.
http://ls1tech.com/forums/automatic-...uch-power.html

The stock 4L80E torque convertor is a monster and weighs a ton. There are a number of aftermarket ones out.... for your power level you are barely tickling the power levels this trans can handle. The internals of a 200-4R look like twigs compared to the 4L80E big brother.

To do a T56 swap as said does cost $5K without blinking an eye in parts once you factor in the trans (T56 Magnum), good clutch/fly, slave, bellhousing, etc.

It seems as though the 4L80E will cost upwards of $4000 by the time I'm said and done for a higher stall, electronic speedo setup etc..

Am I missing something or are they quite a bit more $$ ?

The power loss and weight are also somewhat of a concern. It's mostly about all around driving for me. Car will never go over 700ish horsepower.