[Stdyhand]

I am curious about cylinder heads. I still can't make up my mind on what heads to get because I feel like I will be making a blind decision. I know I could easily get a good brand like TFS, AFR, etc. but I would still be ignorant of WHY I am choosing that cylinder head.

In the end the cylinder heads are meant for a 347 stroker, but I would like to make an educated decision. By that I mean I want to know as much as I can.

For the most part when I look at cylinder heads for sale I only see:

valve sizes

air flow


I've read a lot about how smaller runner increase air velocity thus resulting in increased torque. At the same time some say larger runners mean more HP up high and torque is a product of HP. I've read that runner length effects airflow, thus helping or hurting torque/HP.

How would I find out the shape and length of cylinder head runners? I don't see this information advertised. Even when I visit a manufacturers website it doesn't list this information. It just shows valve sizes and how much air is moved at any given amount of lift.

This doesn't tell me much. I mean no flow bench is the same and they all will claim certain flow numbers at a certain amount of lift. So more information would be great.

How would I go about finding out this information?

[StangBanger302]

The key is to keep air velocity up, while maintaining air speed. Smaller valves increase air velocity while bigger ports increase air speed (flow). Now, on a small bore motor you have to pay attention to valve shrouding. Is the 347 aftermarket or stock block? Stock block will only go to a 4.040 or so, while an aftermarket block will go 4.125 so you can use a shorter stroke. Bore under 4.125 use Trick Flow twisted wedge heads or Canfields. Both unshroud the valves and allow more efficient airflow. AFRs and Edelbrocks are an inline design so their valves are very close to the cylinder walls. Even on bigger bore motors, trick flow heads work very well. All depends on your application...what are your goals? Then we can suggest a cylinder head for you and make you understand why you're choosing that.