440 heads whats better??

If you want something cheap for the street, have the 906s done by a competent shop with good equipment. Have everything done - new guides, spring seats cut, etc. Have them put a back cut on the intake valves with a 5 angle cutter-type valve job. That work will get you the same or more than quick hand cleanup. Then bolt them on with a cam that's small enough to keep the valves out of the pistons. Safe your etra money for a decent convertor and/or some gears. Then run it. That should give you close to an honest 1hp/inch with some great torque. Enough to run low 12s or quicker with good matched driveline parts in an A body. The engien is only a part of making a car fast. If you only have $3K, only about half can be spent on the engine, with the rest on the stuff to support it.