Will this isolation transformer limit power draw?

I have a Bryston 2B amp, and I know it doesn't require more than about 300 Watts in stereo mode into an 8 ohm load, but I don't know how much power it draws in amperage.

I want to use a Stancor isolation transformer in front of it, which is rated for 500 watts and 4.3 amps. Is that high enough to avoid limiting the current on this amp?

Please help me out!
I'd be happy to solder in some new filter caps. I'll pop open the case and take a wild guess on where to find them... :) I'm getting bolder with my soldering iron in any case...

Thanks again!
@sean , at normal listening levels he would probably never hit 720Watts. So why would you suggest a minimum of 1000 watts with a very heavy core?

There's such a thing as dynamic compression & non-linear distortion.  Not only could this choke the power supply in the amp on a dynamic basis, it could introduce further distortions into the AC chain from the Iso momentarily saturating.