Thanks all for your inputs. I'm disappointed to report that there is no 425 in my near future. After finally getting the block codes from the seller, he was surprised to discover that his 425 engine is actually a 401. Don't think I need a 63 401 and 66 401 to complement the 65 401 that came out of my car.
After unanimous recommendations for the 425 it's a let down to find that it was a figment of the current owner's information.
I'm still considering John's T-10 though so all is not lost!
Chuck