Hey im a little new on here,
And i just bought a 89 iroc camaro with a 305 the other day. Im looking for more power and my buddy said he has a Brand new set of 350 heads for cheap. And told me that it would really wake up my car, it has been freshly rebuilt with a Holley 600 carb. Will these heads give it more power? Will they even fit lol? any advice is a help! i want to wake this car up!

 

Without knowing what heads they are, its tough to say. My guess is no....they may even lower performance by lowering compression. That combustion chamber is bigger than the 305 ones. Your options are limited unless you go with a head that known to flow (in and out) on that particular motor.

 

350 bore diameter - 4". 305 bore - 3.735".
Never tried what you're asking, but you're looking at a possible clearance issue with the sides of the valves against the cylinder wall. Do some close measuring on his heads. You also want to look up the casting numbers to find out what cc the 350 head chambers are, as well as your 305's. If they're larger that your 305 heads (may or may not be), then you're going to lose performance. Otherwise, try to find yourself a set of 305 HO heads instead.

 

I'll get some numbers off mine today if it will stop raining, and i'll get some off of the 350 heads and let you all know what it says, i'll try and get some pics of it, its just a new little play car for me to fix up.

 

How many miles on that 305? Put a fresh set of heads on a worn out bottom and you are asking for problems. We have discussed this issue to death....unless you want to sink a boatload of cash into a 305, the only upgrades are exhaust, intake and a carb. You will net about 30-45 HP, which is a significant gain, but will still leave you wanting more. Either swap out your rear end gears, or just bite the bullet and go with a 350. Eventually.....yer gonna get a 350.....just get it over with. 8*)

 

It has a freshley rebuilt top and bottem end. i would drop a 350 down in to it but id hate to get rid of a brand new motor lol. But im not disagreeing with you guys. as soon as this little 350 goes down or blows its gonna have a built 350 down in it, it already has a 600 Holley carb and a intake. so i guess i hit my limit lol. thanks for the advice guys i'll post pics later.

 

Just found out there aluminum Double hump heads, new valves and springs, Looked them up on Jegs and they said they will fit any small block 305 79+

 

Double hump, or camel hump heads as they were referred to, were performance iron heads from back in the 1960's. Many aftermarket performance heads you can buy today far exceed what the camel humps were. I don't know what aluminum heads you're looking at, but they aren't the "double humps".

 

if you are looking for heads that are pre 87 i suggest a set of "416"s