Hi All,

Just wanted to throw out the question, are 906 cylinder heads better than the 452's or are they about equal? I have a chance to by a set for $100 thats all and I was thinking about it. Also one other thing, how can I tell if these heads have been machined before? Is there a thickness measurement I can take?

Thanks,

Joe

 

Hi Im Gary, and just pulled the 452 heads off my 1977 440. I am putting on the 906 heads with minor porting work, EDELBROCK RPM PERFORMER Intake, and a 750 Edelbrock/Carter carb. It ran OK before with the iron intake and spread bore Holley, but hoping for more with this newer set up. Will keep you posted as to how it runs. This is in a 69 Roadrunner Auto.

 

That sounds great Gary, I was thinking of a similar set up. Did you have any port work done on your 452's? Also do you have to change the seats on the 906's? I am getting mixed reviews on that one. I also heard of guys putting an additive in the fuel and using them stock. One last thing, do you know the CC difference between these two heads and what kind of pistons are you running. Thanks.

Joe

 

They are basically the same head. If I had to choose I would take the ones in the best shape. About the only big difference is the 452 heads came with hardened valve seats for unleaded gas. But once they have had a valve job or two done the grinding will grind the hardness of the seat away. But they flow about the same and have about the same cc's and about the same ports. Most people today just go for aluminum heads rather then sink $500 to $1000. in a 40 year old set of iron heads. Ron

 

You know Ron, now that I decided to put this into an A body that would lighten things up as well. I do plan on Alum in the future, so I guess...Back to the Future! haha.

Thanks man

Joe

 

Got the 906 heads installed and the package works great! RPM Intake, Edelbrock 750 carb. Just need more compression, so will do the bottom end in future and use dome pistons. The 906 ex seats will work for a little while. I dont drive it more than a few hundred miles a year. Has great torque, and good top end. Have to spend some time and money on other areas of the car for now. Only have $500.00 in the whole top end. Used the 452 springs, and a set of .020 thick head gaskets. Did the port clean up myself. Good luck.