[scottj]

agro1,

408 vs 331

331 @ 6000rpm would have 5100lbs of tension loading, or 2100 G's (as in G-force) on the bottom end

@ 7200 rpm it would have 7300 # or 3000 G's of tension load.

408 @ 6000 rpm = 6600# or 2700 G's

408 @ 7200 rpm = 9500# or 3900 G's

The 408 at 7200 rpm is higher stressed, in tension, than the 331 at 7200 because the longer stroke creates higher piston speed. At 6000 it's almost the same as the 331 at 7200

numbers are approximate, I used 1100 grams as the reciprocating weight for both engines which is probably light for most 408's so the actual numbers would be even higher.