k20a (type-r) makes 230hp stock, k20a2 makes 195,and the k20a3 is,well the same as a gsr. and if you wanted to make enything close to 300hp with a b series you would wanna start with a b18c (type-r) it makes 195hp stock and thats if you have the money. the cheapest way to go is probly k20a2 . itbs are way fucking expensive,and you cant really dailly drive that.my buddy has an 02 rsx and hes running k20a2 head/k24 bottom hondata k-pro. made 247hp on the dyno on A tune. stock internals so if he had built the head/bottom. could of got atleast 280hp. you can port and polish and bore a gsr all you want and then yull be were a k20a2 is stock. plus the k series i-vtec is fuckin sick. k all the way.and if you do push 300hp all motor its probly not going to be reliable for shit. but hey if you have tons of money why not. but if you do this your gonna need to sleeve the block with a bigger bore. one hell of a port and pollished head, new valves,springs,retianers,rockers,cams,high comp piston and if your not gonna be able to run pump gas. and your going to have to have a serious fuel set up injecters,fuel rail,fuelpump est...so if you have 20.000 dollars layin around and the chance that that motor gonna fuck up. but if you can get all this shit find some one who really knows what the fuck there doing. so i hope this solves the gsr or k20 problem,and ends this forum