04 5.7 Truck motor what heads to get to upgrade?

If you’re already 6.1 headers and 6.1 intake in my opinion 6.1 heads is a no brainer. With the 6.1 intake you can ditch the spacers, with the eagle heads you still need them. The ports of your heads can be opened up to match the 6.1 stuff, and would flow similar if ported by one of the big vendors, but the 6.1 heads also have bigger valves, lighter valve train and smaller chambers. My plan is 6.1 or eagle heads with the mild bowl porting and quality valve job like I mantioned to get a little extra bump in flow on the nicer heads. Lx forums you can find 6.1 heads for $600-900.