It's sacrilege in my humble opinion. To replace a Jag Six with an americian v8 in a E-type. The jag six is a powerfull engine with tractor like torque. I have fond memories of tearing up country backroads and doing third-gear starts, in LA/ Orange county back in the late 70's with my Dad at the wheel. Yes he worked on it a lot. With three SU carbs it never really ran right but, I was the envy of all the neighborhood kids on the block.
Seen a few Big-Block conversations in a Jag Sedans that got my blood pumping
Yes still a muscle car fan