I have a 4L60E and i was wondering just how much horse they really can handle. My freind said he read somewhere that they would only handle to about 400hp. Is this true?

 

it all depends, some are factory fraks other are crap, kind of along the same line as the 10 bolt they gave us, those bastards

 

Stock 4l60e 350 to 400 hp on a good day ,
they can however be built to handle 700 plus hp I have seen built one with the right parts dyno 680 rwhp and never miss a lick .Trick is simple knowing what you can and cant do, excessive preasure bad , Volume good,blocked accumulators bad, More frictions good , larger servos good , wide bands good ,
Most just try and raise the line as high as they can but that may keep clutches from slipping but it breaks hard parts
performabuilt

 

not so much power....as heat, wear, and rpms...