1985 iroc tpi 305 has 215 hp a 1987 350 tpi has 220 hp why does everybody say dump the 305. i going to rebuild my 305 tpi because 5 hp is not that much more. and maybe with a diffrent cam than stock i think it could give me 5 to 10 hp more. the cam i am looking is SPEED PRO CS1014R 204/214 DUR @ 50 .420.443 LIFT. what do all of you think.

 

I think it's a waste of time.
Regardless of what your factory ratings may or may not be, you will generate more torque and more power at a lower RPM with the bigger motor if all other factors remain the same.

 

Forget the factory ratings. Even if you're leaving the 225 HP 350 ( NOT 220 ) pure stock, it has 10 more peak HP, but far more average HP. The torque is the reason, the torque is what you drive, what you feel. Wrong cam for either one, but the 350 will give more improvement from a cam swap, if your choice is a proven upgrade. The cam you chose WILL cost you enough lower-RPM torque that you WILL feel the loss. By the time you buy the cam, and gaskets, and pay shipping, you could have a good used 350 for the same investment.