273 has a steel forged crank.some early318s have the same these cranks are almost exactly the same weight...273 rods are nice light weight with floating wrist pins and so are318 till some were in71 year the rod weigh identical. Later318 rods are 360 castings same as340 minis floating wrist pins. 273s have a very heavy piston wrist pin combo from the factory therefore the factory 273 has very little weight advantage over the318 in stock configuration. You probably new this already but this is for those that don't.
