Not a 9 thread but it's an option:
https://svtperformance.com/threads/passenger-side-head-400-co.1178917/
Can i ask. Can you not use the GT500 heads for your build?
If I am correct, the exhaust pattern is different? Also intake clearance issues? I have ARH 1-7/8th longtubes that I want to still use with this build.
Or I could stop being lazy and just use the heads on my current motor. I was just hoping to swap the longblock in all in one go and keep my old longblock.
But then I need to sell a set of mismatched cobra heads lol.
I see. Hopefully someone will come up with the 04/05 head you need