273 and 318 used this forged crank as long as they came with a forged crank, 69 273 automatics were cast as were 69+ automatic 318s for a while then even manuals got cast cranks, I am not sure what year the manual 318 went cast. The only significant difference in this and 340 crank is the drilled journal, the 340 had a heavier rod and piston requiring some weight removed somewhere to balance it so a hole drilled in the journal it was. You could run a really light rod/piston to get close enough to balance it normally or better yet, drill the hole AND run light rods pistons AND balance it properly to make it real light and strong.