I wouldn't waste your money on stock -ported if you want alot of horse power. I would, if you have the patience build your own c-4. I would have loved the overdrive of an AOD, but too expensive for my blood. I spent 410 in parts. That included all new seals, thrust washers, hardened and lightened direct drum, hardened forward drum,both machined for an extra clutch and steel,kolene steels, raybesto blues in the direct and tans in the forward, transgo shift kit(manual valvebody conversions comes with). It shifts hard and fast, does not flare up at all. Even on the bottle. I built it for 600 hp and a transbrake. I don't use one, but he told me that it would handle it. PM me if you want his #. He know his stuff on the old trannies. He also told me how to modify the pump and case for better lube.