Hey H20 Hammer,
I fish the Old Man River, on the opener for Eyes, Its always been won with cranks in the 3 1/2" range , I won it 2 years ago with one of my hand carved Sunfish cranks, 3 3/4"... I want to try this year with the softbait spinner combo's that I've been working on this winter That's why I said you might want to do a 3 -4" mold, I know it isn't cheap to have one built...Altho some food for thought, with the right multi bladed spinner creating the thump you might get away with a 2 1/2" body
I dunno if this helps at all?