This is from www.netgearhead.com , which is a local shop fo me.
An example of a Stage 3 rebuild on a GM 700R4 / 4L60E would be:

-Transgo or B&M shift kit
-Billet servo
-13 Vane Pump Kit
-Kevlar Oversize Performance Band
-Red Eagle Clutches
-Kolene Steels
-29 Element Forward Input Sprag
-High output Pump Slide Spring
-Heavy Duty Sunshell
-Rear Planet With 5 Pinion Gears
-Heavy Duty Pan
-.500 oversize tv boost valve
-3-4 high performance clutch pack
-Performance 1-2 accumulator spring
-6 Month Unlimited-Mileage Warranty***

They say it's good for 550 HP and 550 ft/lbs. of TQ
Does it look like it would hold up long under that much power? If not, what else would need to be added?

 

Would it hold up to 500 horsepower? I couldn't tell you that, but it looks like a good set up, but make sure they install the high performance transgo kit or else your wasting your money.

 

I second that!!! Trans-go all the way!!! Just ask the professionals (Pro-Built, transfixleo, ect) that is all that they recommend.