Or buy a 351.
Seriously, anything is possible, but going fast costs money. To get a 75hp increase at the wheels, you're looking at a 100hp increase at the crank. If you're at 200rwhp then you're at around 260hp at the crank. Not unreasonable considering your 302 was probably around 210-230 hp originally without all the ancillaries on it, so the low-hanging fruit improvements are done. A cam and therefore lifters ($250 at least) would add potentially another 20-40 hp, but you'll probably need better springs ($150) to handle more lift with more load at higher rpm and you can put those on without removing the heads. However, if you're not confident in your valves being strong enough then think of replacing them ($250) - and if you're removing the heads for that, get them ported and surfaced for more compression ($500-$1000 depending on how far you go) which will give you another $20-40 hp. All this will be nice, but to FEEL faster, get the rear gears changed to 3.25 minimum, maybe 3.5:1 or more ($300 for gears, $500 for someone to fit them) and if you're pulling it apart, get a tru-track or similar $dunno, but hundreds) and it will certainly punch you in he back when you nail it. To deliver on the higher HP numbers (some of which will come from higher revs) then you need to feed it, so consider a bigger than 600cfm carb - if you have an auto, a vac-secondary carb will be fine, probably a 650/700. More than that is too much, and I have a suspicion that the 600 properly sorted will be enough.
Suddenly $2000 is looking quite cheap, and $3000 is just around the corner. How fast did you want to spend?
