A518 verse 727 transmission question

maca said
Hey guys
I currently have an A518 transmission behind my turbo small block in my 1974 aussie valiant charger. I'm making just over 600hp at the wheels. I'm not sure how much horsepower the A518 can handle and I'm not sure how long it will live at that horse power. I would love to keep the Overdrive for cruising on the highway. I have noticed that a lot of the bigger horsepower cars have the 727 not the A518.
I know they similar to a 727 transmission with an Overdrive on the back but how similar are they. Do they use the same parts to build them and can it handle the same horsepower. Can anyone point me in the right direction to work out what needs to be done to my transmission to handle that horsepower and if it's even worth doing.

The diesel boys have been using the A518 behind lots of modified diesels that produce lots of HP and tons of torque, so the A518 can survive. If you go to www.tcsproducts.com you can see what they are manufacturing in the line of HD parts for the 727 and the A518. These items are not inexpensive, but they have been designed to cure the common problems found when you're asking the transmission to live beyond the power level it was designed for by the factory. E-mail Paul Parkins there and he will be more than pleased to answer any and all questions you have.