[olddog]

Engine displacement is not paramount in deciding what engine belongs in any car. Due to NASCAR rules back in the day, almost every manufacturer had a 427 +/- engine.

So an original Cobra has an original engine in it. The small block cars came with 260 cid and 289 cid engines, while the 427 Cobra came with 427 side oilers and 428 center oiler engines. Now on a rebuild the cylinders are bored 0.020" over. The engine is now a few Cubic Inches larger than it was originally. I do not think anyone would argue that the original engine is no longer the original engine because the cid is different.

So in short a factory LS engine of 427 cid does not belong in a Cobra more so than a 427 FE side oiler that is bored and stroked to 482 cid. Cid is not that important. Certainly not as important as the engine family, like an FE.

Last I looked, Ford racing sells Windsor 427 cid engines. They are everywhere. So you do not have to go to Chevy to get a 427 cid engine. This is not a valid reason to put a Chevy engine in a Cobra.