V6 vs. L4
The V6 is wider than an L4, but less than a V8 because the bank angle is 60° rather than 90°.
A V6 is narrower than a V8 with the same deck height.
A V6 is lower than an L4 with the same deck height.
A V6 is shorter than an L4 by at least 1 bore pitch distance. Engine length (minus the front accessory drive and bell housing) is roughly the number of cylinders in 1 bank (V6 = 3, L4 = 4) plus the width of 1 connecting rod (use 1" if not sure). The V6 will be at least 4" shorter.
A modern V6 is well balanced: 60° bank + 60° pin offset, the L4 requires counter-rotating balancer if over 2.2 liters.