When the hood goes pop... What makes the jaw drop?

Its that all exciting time for me again. I'm headed overseas and I'm going to start blue printing my next build while I'm away. The blank canvas is a 69 barracuda coupe with the leaning power of tower. 100% original with 96k miles and only slight surface rust. After spending sometime contemplating which direction I'm going to go in, I started to wonder if there was an end all be all. A build that's at the top of the food chain. Now this is not another one of those "what should I build" threads. Not at all. This thread is going after the wow factor. A little survey one might say. If you walked up to an A-body at a car show what would make your jaw drop... When the you heard the hood pop? With no budget in sight. 340? 416 stroker? 440? 426, 472, 572 hemi? What about some boost? Or maybe something as crazy as an srt4 swap? What?