86mm is 3.386 inches, so a lil more than the standard 3.315 SBM stroke; but not quite as much as a 3.58 from a 360..
But even the 273 has a bigger bore at 3.63or ~92mm
But lessee, to be square a 3.58 stroke 273 is almost there,lol. That's 296 cubes
And the 408 starts out life as a 4x4
Jus ruminating...
