that compression ratio screams forced induction. i would recomend a junkyard Turbo setup, a pair of turbos from either some volvo GLT or mustang SVO/ thunderbird turbo coupe will work wonders, also you can do ut without removing the engine or get into a major rebuild.
6-7 psi shouldnt kill the 305 even with cast pistons and it will add about 40% power putting you in 250Hp land (340 if your 240 Hp estimate is correct but i doubt it) it can be completed for less than 1000$ all (and cheaper if you dont intercool which shouldnt be nessecary with only 6 pounds of boost)
and being 17 is there a cooler sound than that Whoooshh sound a blowoff valve makes when you let off the gas passing your buddies in the parking lot.
I think you will love to brag about a twinturbo V8, love the fact that its so easy to do (do a searce on this site, there are several links to good JY projects that all were completed for way less than 1000$)