6.3 liter Datsun!
When the engine in my Datsun 240Z needed rebuilding, I got carried away.
I figured, "If some is good, more is better, and too much is just enough."
In its original configuration the engine had 6 cylinders inline and displaced 2.4 Liters. Now it displaces 6.3 Liters (383 cu.in.) in a V-8 format.
This photo shows the block having the main bearing caps align bored. The center three two-bolt main bearing caps were replaced with four-bolt steel caps.
Note the use of aluminum cylinder heads and water pump. The finished engine weighs less than the original.
There are some who suggest that this is really a small block Chevrolet with Datsun emblems on the valve covers. I would never do such a thing. Honest.