I started down this road initialy, have a TC that could be used as a donor, but with a little research found that the 351 with aluminum heads and many bolt ons would be within fa few pounds more power and should be more reliable.
This is why I was adamant about marque inclusive in the formative days. I was spending quite a bit of time on the "Cobra" forums researching since I'm doing a "Cobra" minus the body. It becomes rather tiring sorting thru mine is an original , yours is a kit made by the original builder, your kit fits a VW, ETC. "I CAN SPEND MORE $$$ THAN YOU".