I share the thought but can't speak from any experience as I'm a total newb to detroit iron. If you have autox suspension setup questions or 80's german tech questions I'm your guy... I am having fun in the land of pushrods although it's early days for me ~1 year in.

 

Valve angle also matter guys.... which is why trickflow heads kicks ***. Just saying....

 

From what I've seen cruising many sites and forums along with what I've felt driving different trucks, cathedral heads are better for low rpm torque and rectangle heads are better for mid to upper rpm hp. That's the reason gm kept the 243 heads around for the 5.3 Silverado but retired them for the 5th gen Camaro.

 

Rectangles is not always better up top or midrange eithier. Picture is worth a 1000 words.

 

Care to elaborate, for those of us who don't know what trickflow does with valve angles?

 

I know what he's talking about. The angle of the valve relative to the bore center axis. TF's heads (AND Airflow Research's) have the valves closer to being linear with the bore center axis. I believe stock is 15 degrees, where TF's heads are 13.5 degrees.

 

Don't Trick Flow heads require aftermarket rockers?

 

Order the Trickflow heads from Brian Tooley and he can set them up for you to run the factory rocker arms......

 

So, there was this Dude that strangely enough was born in my home town.... ran a little shop up in Michigan called Wheel to Wheel.... moved down here for a while had a little shop down here and was my neighbor in little old Clayton... he has since moved to Texas.... but that's another story... any ways, he told me that if he ever wanted a set of stock GM LS heads done, he would go down I-40 a ways and hit up this shop called Advanced Induction... He seemed to really like them and their work......OH almost forgot... his name was Burt Urban or something like that....He kinda knew his stuff, so I think that's where I'll take my 243's when I get a chance... just saying....

 

You talking about Kurt Urban. Yeah he's good but only build stuff for a certain group of people.

 

Technically they do but the only thing that keeps you from using the stock ones is two tiny little tabs on the bottom of the factory rocker arm stands, all you have to do is grind them off. They are very small tabs.

 

I spent years going back and forth researching heads. In the end, the best results for 243 heads were:

Stock valves - Advanced Induction 226
Larger valves - Total Engine Airflow stage 2