Ford 302 SS build

[ShipC1970]

Originally Posted by Doug Hoven

Depends on whether you call it a Ford or a Mercury 302. If run as a ford, it gets the 450cfm version of the motorcraft 4300 spread bore, air valve secondary carb. If called a Mercury, you are allowed to run a 600cfm 4150 holley.

Why is that and how is that? So I have the original 70 block and matching heads. So hypothetically even though it’s from a ford mustang and I run it in my mustang in GT/QA or PA and say it’s a “mercury” engine I could run a 4150? Who checks this by the way? Forgive me for all the questions I’m new!