Nope. 24A is pretty low. Anyway, 300W is kinda low for a P II x3 and a 4670. You MAY be able to run it, but it won't be stable. I'd recommend a good branded one for 375+ W. Best thing is to get a Corsair VX450. You'll get your bang for the bucks.
I wouldnt think for one minuite that the card would give you a problem, i dont know the power requirements of the CPU but as you have 2 Rails it shouldnt be an issue.
Strongly agree with this though.
"That having been said, I would always recommend replacing a PSU like that with a good quality unit. "