well, as stated, they are more sq amps. it will do rated, usually a tad more for headroom. i may even buy it off ya, or work a trade, if you want. it is normal for them to have rust-worming and likely a noisy fan or toroid squeal. 12.5v 4ohm 75x2, 14.4= 150x2@4, 300x2@2... i have a couple 400's i run in the pickup.