im being as sincere and non-dickhead as possible when i say this, but you read too much into the internet. 300 hp- 15% drivetrain loss would equal 255rwhp. if you use the top number of 235rwhp, that means a 20rwhp difference. underdrives will add about 7-9 rwhp and a cai will add about 1 if lucky.
I have no experience with fuel injection but i have seen with my own eyes (dynojet) (I am not just going by what i read on the internet), a gain in 5-10 horsepower with a cai, and i think drivetrain loss is more like 18-20%. I'm not exactly looking for 300 horsepower, i was just curious. I guess its not possible.
You would need to make about 250rwhp to have 300 to the crank. I think you would nee more then just pulleys, and a cai(<--they really don't add any hp) to get the 300 you are looking for.