It really depends on how fast of a street car you want ?? If you want to beat alot of these newer cars then you might want to shoot for 11's. I mean I saw a Mercedes at the track running 12.40's that I believe was the supercharged V8 deal. I figure my 63 makes about 500 hp at the flywheel to push it at 3700 lb's to mid 11's and it really is a very mild 440 by todays standards. But with an A-body the smallblock stroker is the ticket. Very easy to get 450 to 500 hp and that would put your A-body well into the 11's and still be very streetable as you can do it with 3.91's as that's what my son uses with the 400 in his Dart. Good luck , Ron