Engine swap

To drop in a V-8 you will not need a different K-member >> they are the same from 63-66. You will need a V-8 centerlink and motor mount brackets (mounts are available through Schumacher).

The most difficult part of your swap will be the firewall modification required for distributor clearance (as pointed out by Rob64GT, the 63 didn't come with a V-8 so the mounting area for the wiper motor interferes). 64-66 vehicles had a different firewall, and V-8's fall right in.

Clearance can be achieved either via a BFH, but surgically cutting the periphery of the mounting panel for the motor and pushing it into the passenger compartment by about an inch is much cleaner.

Another challenge that us early-A types wrestle with is the availability of exhaust headers. There are some options out there, but only two under chassis flavors >> Dougs and TTI, though some would say that Spitfires are another option but sometimes availability becomes questionable.

Good Luck!

p.s. - I've never heard the 225 referenced in liters before!:read2: