408 stroker header size

I'm in Canada and can only seem to locate the Doug's headers here will these suffice for my motors power output? I need to call to see what oil pan options they have.
If you live near a border there is likely a company that accepts packages on the American side. Then you just have to go drive and pick it up and bring it across the border and pay any tax on it.
I order direct from tti. (Twice now)

They will ship it to your Canadian address but it's the unknown custom and brokerage fees some companies like to charge.