Have you tried the local salvage yards? A few years ago I needed a few 235 head bolts and bought a "sack of bolts" from a scrap yard. These are used. If I can find them, I will ship them for shipping cost. Send me a pm if you are interested. As truckernix says (and also explained in the ARP catalog, I think) the the body is turned down to control the stretching and, possibly, to equalize the preload in the long and short bolts.
