It's very late night commenting here, so I hope not to offend. The notion of a "Cobra" not having a real 427FE one supposes sounds more like a 1970's kit car discussion point intended to highlight the fakery and show disdain for the whole notion. Admittedly in the 60's and 70's kit cars were not focused on replicas in the sense they are today. Some early "Cobras" back hardly resembled the real thing, if for no other reason than Shelby would likely sue them.

Having grown up when these were all actually around, I remember the 289 Cobras way more than the 427's, because there were so few of them if nothing else. Plus, they were so over the top and had surprising handling issues so that people died. I think the 289's were about $6000 and the 427/428's were $8500-ish, when a new Lincoln Continental was $4500 and a Ferrari 275GTB was all of $14,500. The 289's were extremely fast, especially the optioned ones. You could actually order the 4 Weber package as a standard "factory" ("hangar") option. I swear I remember that some of the motors were 302's or something close.

But, when you can put an extremely light SBF 427 in there, or an SBF-anything, that makes 500 flywheel hp in a 2500 pound car, and doesn't ruin the handling by having a refrigerator nestled in the engine bay, why wouldn't you do that? Smallest, lightest engine pulled back as far as possible to the firewall and move as many ancillaries as possible back to the firewall and the car's even more front-mid-engined.

Gordon

Interestingly, the OP is looking for a SBF 427, not a 427 FE - so it appears he's looking for displacement to match the badge on the fender, not an engine faithful to those used in the original 427 S/C cars.

I must be missing something, as I don't understand the obsession with matching (or exceeding) the number on the badge.