426 stroker kit

GUYS GUYS , Both of you have contributed GREAT INFO for me and the forum. THANK YOU BOTH.
My hope is to build a strong motor on a budjet . I have thousand spent on my car and still on stands.
I was referring to all 4.05 or 4.08 when I said 4" . But im glad that it opened a couple of question?

1: can I up my motor using the stock 6.1 crank?
2:i really want to use a manley crank but by the time I bring it into Canada pay all the bs. taxes duties and sh#t . Im into 1200.00 .

John