Shelby heads vs. Edelbrock heads

[btsai]

I recently read that the Shelby heads have a 2.250/1.750" valve package, as opposed to the Edelbrock's maximum of 2.19/1.73".
So, is it possible to have TOO much breathing ability? I also haven't priced any of this stuff so if the Shelby is more $$$, would this difference make it worth it?

Just curious.

Ben

[SFfiredog]

I thougth the Shelby heads came with 2.19 in and 1.75 exh? One problem with the Shelby heads is the valve positions. Edelbrock relocated the valve slightly in relation to the cylinder. This allows for less shrouding of the valves by the clylinder walls. The biggest valves and ports in the world won't help if the mixture entering or exiting the engine is blocked or interupted by the cylinder walls. Airflow is all about the proper combination. All of the big name FE engine builders I know of are using the Edelbrock heads. Money is not a concern with some of these builders so if the Sheby head was better, they'd be using them.
my .02
--Mike

[concobra]

I have Edelbrock heads. I am running 2.25" intake & 1.75" exhaust valves. They do fit without any special machine work required.

Also, I suspect that the "Shelby" heads are Edelbrock units. Look closely at the ridge on the exhaust port on the "Shelby" heads. It's the same thickness as the Edlebrock heads. I believe that this thick ridge is unique to Edelbrock's castings. Also, since Edlebrock manufactures the so called new "Shelby" dual plane and single plane manifolds, aka the Edelbrock Performer RPM & Victor JR. it only stands to reason the heads come from the same place.

I could be wrong and if anyone knows for certain I would like to know.