i would say you are correct .. the C5 is a 65 casting year .. doubt they were making 302 rods in 65 ..if they have 3/8th rod bolts i`d find a 289 crank and use them ( hi-po ) rods.. i have a couple hi-po rods left over from a bogus boss 302 build i did a thousand years ago that i will tell in car stories some day .. i p/md you a suggestion