Do you mean a 302ci Saleen engine with a supercharger from his SMS 302?
http://www.smssupercars.com/302.html
Essentially, you can put whatever engine you would like in your Kirkham, but it will depend on how much modification of the car you want to tackle and how much uncertainty about resale you can handle.
Nearly all 427 Kirkhams have FE's. I can't think of too many with non-FE's.