I thought you were already putting a V8 in it?
My guess is a 10-15hp difference. If you go from a not so good running 1bbl to a nice running 2bbl, the hp difference could be even greater.
Adjust your valves and make sure you have the correct spark plugs for a cheap and easy way to make sure you're getting all you can out of the motor.
Get rid of any dead weight in the trunk and cab like extra tire irons and all that.
Super six and exhaust are a good start. After that, taking a little off the head is the next step. From them on you're gonna need a lot more cash.
