GT40P will be fine with SD. They don't affect manifold vacuum or airflow enough to be outside of the range the map sensor and ECM are looking for.
Twister over on AFM ran the Ford Y303 heads with speed density and the cam I posted above in his car. I actually drove that car between Gateway International Raceway and I-55 Speedway back in 2003. Other than a tendency to hunt for idle speed until it warmed up, it had excellent drivability.
I'm not hating for wanting to switch to a carb, you should see in my build thread where I pondered going carbureted on the 4.6DOHC I'm putting together for my car. In the end I'm going EFI there for the same reason I recommended you staying with EFI, it's actually going to be cheaper.
Nevermind. Forgot ill have to change exhaust on gt40p heads. I just want to be able to throw it back together for now and run it. Ill use my other block for the real build. Thank you for the advice. Didn't know I'd get so much hate for mentioning going to carb. Lol
I wasn't hating on you for a carb swap.
Ok, maybe a little.
I've seen too many carb swaps that ended up junk with hacked wires and fuel systems and honestly when I see a carb swapped efi car at a show I don't even look even if it's really nice.
I rate carb swaps right up there with pias ply tires and mullet hair styles.
Glad you changed your mind
I wasn't hating on you for a carb swap.
Ok, maybe a little.
I've seen too many carb swaps that ended up junk with hacked wires and fuel systems and honestly when I see a carb swapped efi car at a show I don't even look even if it's really nice.
I rate carb swaps right up there with pias ply tires and mullet hair styles.
Glad you changed your mind
Lol even if I did do the swap trust me it would be trash. I mechanic for a living and very anal of how my work looks but do understand what u mean. It drives me nuts seeing how people do diy custom jobs and how disgusting it looks.