427 or 428 - How do I tell?

[Excaliber]

I hear that a lot, more Cobras with 428's, I don't think that's the case, but it could be argued. Folks were pretty upset when it was discovered that 428's were being used. A number, perhaps "many", dumped the 428 and had a 427 installed. Shelby caught hell over this and replaced some at his own expense. The later production cars returned to using 427's because of the out cry. The "name" 427 Cobra actually meant something (unlike today where anything goes). Like a drag race in San Francisco is two guys dressed in drag running down the street,,, things have changed, it just aint the same anymore.

I recall the big blow up people had over finding Chevy motors in Old's and Pontiacs some years later. Back in the day, you didn't mess with stuff like that, it just wasn't done.