I have an 89 camaro, 71k miles on it. Runs good, is a dog however. I have a relative willing to give me some parts from an 85 firebird he is scrapping. He has the 305 HO engine. If i take the heads, intake and carb off the ho engine and put it on my 305, will i gain a lot of power, or will the effort not be worth it? I would probobly end up putting on a new holley rather than the original carb as the car has been sitting for over a year. what do you think?

 

Don't quote me on this but I think what made the HO (L69) was the cam and higher compression pistons and larger exhaust. I think the heads/manifold and carb were the same.

 

Except the heads and exhaust of the LO3 are maxed out at 170 HP.

L69 CR was 9.5:1, LO3 9.3:1. Insignificant difference.

L69 cam was flat tappet, LO3 roller. Won't swap between the engines.

Put the heads, intake, and carb on, you'll need the distributor, ECM, harnesses, etc., as well. If you put a Holley on it, you'll need a vacuum/mechanical advance distributor that neither car has as well.

While you've got the heads & intake off, put in a better roller cam (you can reuse your roller lifters), and replace every single piece of the exhaust with '86-'90 TPI single cat application headers and exhaust (or, at least the HO exhaust).