With the intake included, it's definitely on the "large" end of the V6 scale. Without the intake, average size and weight for a DOHC V6. It's heavy, because of the iron block and the large intake.
A straight 6 will be longer, but narrower (of course). Most DOHC straight 6s of around 3.0 displacement will be heavier, if they are iron blocks. The V design saves weight over an inline engine.
A rocker V8 (like an LS series, SBC, old 5.0 Mustang, etc) usually ends up being about the same size/weight as the SHO, but a DOHC engine will be larger. An all aluminum V8 will usually be lighter.