sfi flex plate loose, help

so i bolted my new flex plate to the motor using ARP bolts, for 318-360. i torqued to 75 lbs like arp said, but the flex plate is still loose, if i use a shorter bolt, like a converter bolt the problem is gone, should i just shorten the arp bolts and red locktite them? ARP wont warrnety anything if i use washers