To get anything close to 260rwhp you will need alot more then just bumped up compression.
my old boss has a VS Speedway car runs a ecotec v6, standard stroke, knifed edged crank, balance shaft removed, runs external oil pump, external water pump, monster cam, around 5k invested in the heads, ported stock manifold, standard throttle body (class regs) compression ratio of 11.0:1 v6 supercharged injectors, kalmaker software runs vn ecu with tune to suit. made 258rwhp
you wont come out wiht much changed from 10k there
good luck getting 260rwhp out of just shaved heads.