The reason they changed the heads was so they could make a big horsepower number, can't really make 1300hp on small heads and nobody wants to read an article without a big hp number. Basically it looks like whatever you can fit through a stock head the rotating assy can handle. Wonder if the reason they stopped was because of the fuel bill 70 runs is impressive.

In the end it's all in the tune up...

 

Subscribed to read this weekend!

 

While thats true.. that would have been a fine example to sell trick heads..
comapre them to the stockers. Show how much they are held back..

 

Im still impressed they got 500+ out of it NA while dropping .5 from the CR. Pretty big cam and heads for a 5.3L. Looks like Im not gonna hold back from 10-12psi on my 170k+ mile engine. Should be good for 500hp and drive and act like stock since Im not gonna touch the long block.

 

I have a cheap 02 for ya. Too bad we're on opposite ends of the world

 

that is VERY impressive 500 out of such small CI with stock internals. i sent this article to my tuner and he responded with "new project!" lol if i had a place to rip my truck apart indoors for the winter i may pull the blower and go turbo. need a cage also because 11.50 should be a breeze

 

Just shows what good tuning, good fuel and no knock does for you.
Who needs a race engine but a bunch of stockers.
With cam and heads. Let it chew.