For a A-series I think about 90HP at the wheels would be a good goal, fairly roarty but not a total pain to drive on the street. Standard stuff, ports cleaned up on the head, camshaft, side draft carbs etc.

Keep some money aside to upgrade the brakes and suspension. I always say in these posts to get the whole package. Decent Dampers, sway bars, decent wheels and tires then add the power. I'd rather give up 10-15 horsepower on a street car for something that is more usable.

The two killers and limiting factors are gear box and rear end, you can easily spend half your budget on a diff and good gearbox. If the gearbox has huge gaps you won't make the most of the motor and if one tire spins like mad all the power in the world is useless.

As mentioned take your time get some deals and in year or two you'll have a cool car.

Tom