Yea I know! Not another 351 Head swap question. I did stay up to 3am searching the forum and the net and found a wealth of information. One thing I did not find was what the "actual" gain I would have over a stock set of heads on a 289 engine.
I know they have bigger valves and ports, an I also know the compression suffers because of the larger cumbustion chambers. Also that removing the bump in the exhaust port will help with the flow, and a the variety of ways of mounting them, etc. etc. What I haven't found was what kind of gain they actually got "after" doing the swap?
I have a set of 69 351 heads I am considering putting on my 66 289. If I do, I will have the heads milled to reduce the chamber volume to as close to 54 cc as has been suggested to increase the compression. I am not tearing the engine down, so replacing the pistons is not even a thought. If I use the 1.9 & 1.6 Chevy valves, will I need to use shorter pushrods to accomodate the Chevy valves?
The 289 engine has been bored either .20 or .30 over prior to me buying the car. I have a set of shorty headers, and will be adding 2½" exhaust with a "H" pipe. Also will be using the Pertronix II and Flame Thrower coil. I'm also thinking of using a Torker-Plus cam, or something similar to those specs. And yes, I will be using the Edelbrock dual quad set up I recently obtained, and no I won't sell it for a single carb set up as has already been suggested.
So what kind of gain over the 289 heads will I see in extra Torque & HP?
JohnPro, Camachinist, Anyone?
I know they have bigger valves and ports, an I also know the compression suffers because of the larger cumbustion chambers. Also that removing the bump in the exhaust port will help with the flow, and a the variety of ways of mounting them, etc. etc. What I haven't found was what kind of gain they actually got "after" doing the swap?
I have a set of 69 351 heads I am considering putting on my 66 289. If I do, I will have the heads milled to reduce the chamber volume to as close to 54 cc as has been suggested to increase the compression. I am not tearing the engine down, so replacing the pistons is not even a thought. If I use the 1.9 & 1.6 Chevy valves, will I need to use shorter pushrods to accomodate the Chevy valves?
The 289 engine has been bored either .20 or .30 over prior to me buying the car. I have a set of shorty headers, and will be adding 2½" exhaust with a "H" pipe. Also will be using the Pertronix II and Flame Thrower coil. I'm also thinking of using a Torker-Plus cam, or something similar to those specs. And yes, I will be using the Edelbrock dual quad set up I recently obtained, and no I won't sell it for a single carb set up as has already been suggested.
So what kind of gain over the 289 heads will I see in extra Torque & HP?
JohnPro, Camachinist, Anyone?